CH617230A5 - Apparatus for yarn drawing on textile machines, with a pendulously arranged self-aligning load arm - Google Patents

Description

The invention relates to a device for yarn stretching in textile machines, with a pendulum-arranged, self-aligning loading arm, with a housing and a pivoting member, the loading arm being movable around one axis around the pivoting member of the housing, with driven, rotatable rollers at the other end of the loading arm, with a drive body for driving the driven rollers, with a pressing member for the loading arm, the pressing member being located between the two ends of the loading arm and holding the rollers in engagement with the driving body.

The textile machine can in particular be a draw frame, wing spinning machine or another spinning machine.

In the usual way, the known oscillating load arms have a self-aligning effect and have the structure shown in FIGS. 1 and 2. There is a loading arm A, an arm guide housing B, an arm guide pin C, a drive body (curved or flat surface) D, driven rollers R, a driven roller axis G and a pressing body S.

In a conventional manner, a stretching section of a textile machine has two or more pairs of the aforementioned devices which are arranged parallel to one another, the head roller R on the driven side being driven in each pair by pressing against a bottom roller D on the driving side, where the contact of the two cylindrical rollers forms a press nip with different shapes, a punctiform, linear and planar contact occurring, depending on the degree of parallelism between the axes of the top roller and the bottom roller. In order to obtain a high yarn quality, a high, constant surface contact of the rolls at the stretching section of a textile machine is an essential condition. If the degree of parallelism between the axes of the top roller R and the bottom roller D deteriorates, this results in an uneven change in their mutual contact, so that the two rollers only have a punctiform or linear contact, so that no constant press nip is maintained can, making it difficult to get a smooth and consistent yarn draw that has a direct impact on the quality of the product. Therefore, maintaining the parallel position of the axes of the top roller and bottom roller is an indispensable requirement in the extraction section of textile machines. In order to maintain the desired condition, special emphasis has so far been placed on making the loading arm as precise as possible, furthermore on precise adjustment of the components when assembling them or on self-alignment of the components. If the two rollers R and D are always parallel to one another, the same roller gap with a uniform pressure distribution is constantly achieved over the entire contact area during the rotation of the rollers in their mutually pressed contact. However, such a device tends to assume an unstable position, since it is subjected to the effects of a complicated movement of swaying, rolling and pounding, resulting from the arrangement of the loading arm A.

In particular, in the case of FIG. 1, where the driven roller R and the driving roller D touch along a cylindrical lateral surface, their respective abutment against one another gives completely different states, depending on the degree of parallelism of their axes, so that in connection with the pressing process very uneven press nip is formed.

In short, this means that the stretching section requires a stable and secure press nip. It is also important that this fixed press nip, i.e. H. the fixed contact of the two rollers is evenly distributed over the entire width of the contact area. If the parallelism between the axes of the top roller R and the bottom roller D deteriorates, there is an uneven change in the contact state of the rollers, the printing system changing its linear shape and changing to a dot system, so that it is difficult to make one across the entire width to achieve and maintain the steady investment position in the role. 3 shows the deviations which occur in a self-aligning device in an embodiment according to FIG. 1, the reference symbol a representing the normal state and the reference symbol b and c the different states on both sides. Measurements were taken at the point where the textile machine is used, i.e. not at the manufacturer of the textile machine, whereby it turned out that the curve shape after the

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Line a or b predominates. Maintaining the parallelism between the axes of the driven role and the driving role is of the utmost importance. To date, no adequate solution has been found to always create this condition. To date, there has been no choice but to maximize the manufacturing accuracy of the components from the loading arm, align them precisely in a time-consuming manner during assembly, or resort to a self-aligning design of any known type. However, all of these solutions were not entirely satisfactory. These measures have their limits. In order to meet the needs on the market, it is no longer necessary to rely on the usual types that have reached a dead center, but rather to make use of a new type of construction of the loading arm that has a high responsiveness, that is is very sensitive. This demand has led to various types of load arm designs.

The load arms with which the textile industry works can be divided into the following three types.

Self-aligning type (pendulum arm)

This type can be seen in FIGS. 4 and 5. In this type, use is made of a pivoting movement of a customary loading arm 3, which is arranged oscillating around a pin 6, the loading arm being arranged in such a way that

that it can be pivoted spherically with respect to the axis 6, as can be seen from the spherical surfaces of the arm 3 at the axis 6 in FIG. 4, a head roller 2 being rotated by a base roller 1. Here, an automatic parallel adjustment of the top roller 2 with respect to the bottom roller 1 is achieved. In this construction there is also a spring 4, a housing 5 for the load arm and a base plate 7 for the housing 5. In this construction, two head rollers 2 lie on a common axis, symmetrically to the pivotable arm 3, which is pivotable about the axis 6. The arm 3 engages in the middle between the head rollers 2 on their axis, so that the two head rollers can swing about this articulation point 6. The freely rotatable rollers perform a return movement. This return movement is based on the exertion of a pressure which is produced during the alignment, and although this effect cannot be denied, the accumulation of errors resulting from various factors, e.g. B. in the manufacture of the components, including the deflection of the spring, deviations in the manufacture of the housing for the load arm, the same deviations in the base plate and errors in the bearings, errors to be observed. In particular, due to the recent demand for increased stress, i.e. pressure between the two rollers, the tendency that the aforementioned deviations are even greater. The sources of error are further increased by a second rear roller and the associated lower speed. In the case of the components mentioned, the restoring force is so low that a force which is not great enough to be able to absorb the accumulating errors can be achieved. Under these circumstances, the low-speed component has been transformed into a pendulum, which affects the maintenance of the parallelism of the top roller with respect to the bottom roller. Improving the trigger performance in the trigger area is still a question of time, and this is an indispensable factor in increasing the gap pressure. However, the increase in pressure on the top roller when applying cylinder to cylinder makes it more difficult to align the bottom roller and top roller in parallel. For this reason there is a limit to increasing the pressure to self-align the two rollers,

if the loading arm is designed as a pendulum. Nowadays, such facilities have already reached their limit. Especially when the second roller and the following roller, which are mentioned, work at low speed, there is a retreat, so that the tendency towards distraction is particularly pronounced (see FIGS. 6 and 7). It has been found that the disadvantageous effect that occurs when relying entirely on the self-alignment of the rollers leads to a reduction in the performance of the fiber stretching section in modern wing machines that work at low speed but high load pressure, and that the self-alignment of the Roles to improve quality has reached its limit. In order to remedy this, a method has already been proposed in which a guide piece (not shown) has been attached to the loading arm for correction purposes; however, it has proven impossible in practice to maintain the required accuracy.

Fixed type of load arm

This method can be seen in FIGS. 8 and 9. Fig. 8 shows a type that is not based on self-alignment, the component holding the axis of the head rollers being held directly at right angles by a loading arm 3 such that it can carry out two movements, namely a rolling movement and a yawing movement. In this construction, the loading arm 3 itself is attached to the arm body 9. There is also a set screw 11 and a support pin 12 for the spring. The construction shown in FIG. 9 is similar to that according to FIG. 8. In order to prevent the accompanying phenomenon, namely the lowering of the pressure against the top roller, depending on the frictional resistance for holding the top roller of the loading arm, as is the case with the embodiment according to FIG. 8 is the case, a pin 10 is now provided on the loading arm. As already mentioned, in the construction with a fixedly arranged loading arm, the latter is loaded with a large weight in order to avoid the disadvantages of the initially explained construction, in which an oscillating loading arm is used. In recent years there has been a tendency to use this type of construction increasingly. It is impossible to obtain satisfactory results if the base plate of the housing is not at an exact right angle to the bottom roller and if not all components of the loading arm are made very precisely. If these requirements are not met, the errors add up, as in the construction in which the load arm is arranged in an oscillating manner, as a result of which the measurement results are further apart than can be imagined. In this case the overall error is not very different from that which occurs when an oscillating load arm is used. Although theoretically possible, as with the system with the oscillating loading arm, it is practically very difficult to maintain the parallelism of the top roller with the bottom roller. It can be determined without hesitation that both embodiments, one with the oscillating loading arm and the other with a fixed loading arm, have serious disadvantages with regard to their self-alignment.

This is fully confirmed by the following test results, which were determined in the textile industry, i.e. where the textile machine is practically used. Fig. 6 shows the degree of deflection of the rear head roller in a construction in which the loading arm is arranged in an oscillating manner and in a construction in which the latter is fixed. The degree of deflection of the front head roller is shown in FIG. 7, again with the two different construction 5 mentioned above

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species. In any case, the results were determined by well-known companies on the basis of exact test procedures. Taking into account the measurement data obtained, it can be clearly established that, although the self-aligning loading arm is somewhat more advantageous, the deflection extends over a large range beyond the permissible limits. It cannot be denied that it is not an easy task for companies headed by a large number of company groups to keep the head roll in acceptable conditions.

Taking this into account, it can be said that the basic inspection is very necessary to achieve a self-aligning construction that is also highly responsive, i.e. sensitive, and works maintenance-free.

The constructive disadvantages of the load arm cannot simply be eliminated, as has already been described, but this is not to say that there can be no ideal construction. A reliable measurement can be achieved with the type to be described below.

Adjustment construction

According to the setting construction, as is known from Japanese laid-open specification 72 422/74, it has become apparent how the disadvantages can be avoided. 10-12 show embodiments of this adjustment construction. According to this construction, the top roller is held by one end of the loading arm, whereas the other end of the loading arm is arranged in a pivotable manner in order to achieve an oscillating construction. The housing for the load arm or a spherical adjusting element, which is arranged separately, is brought into contact with its spherical surface with a part of the load arm, and in free contact, so that the yawing movement of the head roller can be adjusted and monitored, the axis the top roller can be held parallel to the axis of the bottom roller, and at the same time the top roller can perform a tamping and rolling motion when following the bottom roller. This ensures that the bottom roller and the top roller move in contact with each other and not separately. This construction makes use of the principle of the pendulum system, in that one end of the load arm is pivoted and the top roller held at the other end with respect to the three axes in a spatial coordinate system, namely in the X axis , the Y-axis and the Z-axis is freely movable, so that the head roller held by the guide arm is pressed against the bottom roller in a point system, line system or surface system, so that the head roller can perform the yawing movement, ramming movement and rolling movement.

In this case the main factor is to maintain the parallelism of the top roller with respect to the bottom roller in the yaw movement of the top roller. If the yaw movement of the top roller follows the bottom roller perfectly, all conditions are balanced and the parallelism of their axes is maintained, so that a constant contact between the two rollers can be achieved. On the other hand, if the top roller cannot fully follow the bottom roller, all other requirements lose their balance and the desired goal cannot be achieved.

Therefore, if a method can be created in which the axis of rotation of the top roller can be kept parallel to a reference axis based on the axis of rotation of the bottom roller, only the yaw movement of the loading arm need be precisely controlled while it freely follows in the other directions can, that means during its rolling movement and ramming movement, so that the loading arm then follows the various conditions that are required for the head roller. As long as these conditions are maintained, the mutual contact of top roller and bottom roller is maintained over a predetermined width, with every contact pressure. This relationship applies completely to the pounding movement, whereas the rolling movement is theoretically influenced somewhat by the yawing movement. With regard to a very small displacement of the deviation of the ground roll, and since hardly any such displacement has a sufficient influence on the yaw movement, the small displacement can practically be neglected, so that the parallelism is not nullified.

The reason for this is apparent from Fig. 12. Assuming that an eccentrically adjusted, spherical surface has the radius R (amount of deflection ô), the displacement angle ß in the yaw direction with respect to the angle der of the rolling movement at the contact point between the spherical surface and the load arm results from the following assignment

ß = R (l-cos0)

It can be seen that β is close to zero with an infinitely small offset of 0.

Various methods can be envisaged for the adjustment construction, and in this connection reference is made to FIGS. 10 and 11. An example of an eccentric construction is shown in these figures and examples of the adjustment construction can be seen in FIGS. 13-16. FIG. 13 shows an adjustment construction in which a locking nut no is used, while a clamp construction is shown in FIG. 15 above and FIG. 15 middle, in which a leaf spring m or ni 'is shown. From Fig. 15 below, a construction can be seen in which a cranked bolt n3 is used. In the example of Fig. 16 above, an elastic body m from z. B. rubber used. In the example of Fig. 16 center, a tube m is used, which is made of a relatively soft metal, such as. B. lead or copper, this tube is combined with an organ that serves to deform the soft material to fix an adjusting pin m in the middle. From Fig. 16 below one possibility can be seen how an adjusting pin is attached by an adhesive or a solder joint ns. Any of the means shown in Figures 15 and 16 can effect adjustment if necessary. Thus, a suitable jig can be formed for each of the constructions to be used when adjustment is required to avoid the difficulties caused by the deflection of the head roll.

However, this procedure requires professional work and a relatively large amount of time, so that it is difficult to do this in practice. For this reason, manufacturers use a static procedure when working with the loading arm to eliminate errors.

In any case, these systems are based on a concept that always ignores the self-aligning function of the load arm, denies natural laws that can be used in an advantageous manner, and some of the suggestions mentioned cannot be implemented in practical terms. These suggestions cannot be regarded as substantiated by measurement results either. However, satisfactory results can be achieved if these systems are provided with a head roller having a wide track width or with very slow-rotating head rollers which contain the mentioned second head roller, the head roller being heavily loaded and its speed being very low. There is also an embodiment in which an s

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Control device in the form of a control bracket is used, which is attached to the loading arm in a wing machine. However, this is nothing more than a makeshift in a slightly different way from the aforementioned adjustable system. A system that continues to be based on a fixed loading arm assumes that the arm housing is always positioned correctly, as is the case with the saddle system used by various leading companies. However, this system cannot satisfy either, as has been shown in practice by some examples, although attempts have been made in this direction for years and results have been obtained. However, this last-mentioned system cannot satisfy from the quality point of view.

From the foregoing, it can be seen that it is very difficult to control and maintain the parallelism of the top roller and bottom roller with a large number of head rollers working in a textile factory, as long as one uses the usual type of load arm. However, if one assumes that the parallelism of the top roller with regard to its bottom roller has a direct influence on the quality, and that the performance and the trouble-free operation depend directly on it, one can judge that there is vital interest in using a new concept here to create the self-alignment of the roles.

From the description, the circumstances and disadvantages of the load arm that is in use today can be seen. The possibility of self-alignment has not yet been fully developed in the case of the load arm, which is arranged in a pendulous manner, since this load arm is still provided with design disadvantages in accordance with the examples mentioned. The self-alignment of the pendulum arm is now considered again from these points of view.

The function of self-alignment can be seen from FIGS. 17 and 18. The basic principle of the pendulum arm is shown in FIGS. 17 and 18. When a drive surface D 'is moved uniformly in the direction of an arrow YY' and the load arm A is pivotally supported by a pin I in the articulation point O, the load arm bearing an axis of rotation XX 'of the driven roller R, the arm A becomes perpendicular to the plane of the drawing on one fixed point P is pressed by means of pressure elements. With such an arrangement, the relationship jojo'IXoXo 'is constantly maintained at arm A if the relationship YY'_LXX' applies. This relationship remains unchanged from the number of rollers, as can be seen from FIGS. 17 and 18, and remains unchanged as long as no outside interference occurs.

The main points of the aforementioned reasoning will now be explained with reference to FIG. 19. The driving surface D 'moves continuously in the direction of the arrow (parallel to the axis YY'), the driven body R is viewed at three points a, b, c with respect to its holding axis xx '. When the driving surface D moves in the direction shown by an arrow parallel to the axis YY ', the point a of the driven roller R is in such a state that this point is in relation to the axis YY7 such that the relationship YY'lxoXoV / XX 'applies. The point b shows a state in which the roller is inclined to the top right at an angle 0 with respect to the reference axis XoXo '. The point c shows a state in which the roller is inclined to the left at an angle bezüglich with respect to the axis XoXo '. In position a, the center Q of the roller R is always on the reference axis YY ', which extends through the articulation point O; here there is no angular displacement on the driving surface D '. On the other hand, in position b there is the straight line yly'l 'passing through the center Q2 of the roller R2.

With state c, the straight line YrYr is present for the roller Ri. Since the roller R has a line contact or surface contact with the driving surface s over the entire width of the roller, the paths Jo, Jl and Jr are described. At positions b and c in FIG. 19, these paths are determined by the angle of inclination 0 of the driven roller R to the reference axis YY '. In Fig. 19, in positions a and b, the paths approximately follow the reference axis YY '. The speed s results from the following function.

s = Vsin 0 ... (1)

This relationship can be dynamically replaced directly by a vector value that has the direction of the force F.

20 and 21, a loading arm is assumed in which a support arm OQ has a length l and has its pivot point O on the reference axis YY 'and holds the roller axis xx'.

As long as the normal relationship XX7 / xox0 // YY 'is maintained and the driving surface D' moves in the direction YY ', the normal position is constantly maintained since no vector is generated in the direction which displaces the axial direction XoXo'.

20 and 21, in the case where the driving roller R is in the position according to Ri and R2, it can be seen that in the position Ri a vector Ti is created which is assigned to the driving vector V. The vector T1 lies in the direction of the axis Xi Xi 'of the roller Ri. This force produces a torque M in a direction equal to the direction Ti /, the pivot point being at point O on the swinging arm in order to bring the loading arm back into the direction which corresponds to the reference axis YY ', since the roller Ri is arranged transversely to the swing arm with the length /.

M = Ti 1 ... (2)

In this case, a vector is obtained which corresponds to the force component in the axial direction X1X1 'of the driven roller Ri. B. the force Ti that is generated in the role Ri

Tl = Vsin0 ... (3)

It is thus evident that the force is a function of the deflection angle 0, which is formed with the reference axis XoXo 'of the driven roller Ri.

From formulas (2) and (3) follows

M = 1V sin 0 ... (4)

From this formula it can be seen that the restoring moment M does not disappear unless the angle of inclination between the axis of rotation XX 'of the driven roller R and the reference axis XoXo' of the driven body with respect to the axis YY 'of the driving body D' is stabilized in such a way that is the angle © = O. If the angle is 0 = 0, the torque is M = O and the swing arm is stabilized in this position. In the case where the driven roller takes the position R2, the angle 0 receives only a minus sign and the various relationships remain unchanged.

The above-mentioned theory applied means nothing other than the pendulum arm.

In this way, point O forms a pivot point for the oscillation of a conventional load arm and thus forms the characteristic feature of a pivotable support system, and at the other end holds the driven roller R at exactly the right angle. When pressing the load arm s

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a spring is usually used, e.g. B. a compression spring, e.g. B. coil spring or a leaf spring. Fig. 1 shows a typical example of such a construction. In rare cases, pneumatic or hydraulic organs are also used to exert pressure on the loading arm.

Whichever system is chosen, there is always the task of exerting pressure on the upper side of the loading arm.

As long as such a concept is used, there are various disadvantages. So z. B. from the usual example of FIG. 1, in which a spring is used, hardly to assume that a pressure vector or a pressure distribution occurs in the mutual contact area of top roller and bottom roller, which corresponds to the theoretical uniform distribution in the normal position of the loading arm.

As mentioned, occur with the existing types of pressure, for. B. by coil spring or leaf spring, individual, very scattering and significant deviations, and the pressure direction of the spring also has the tendency to deviate in a wide range from the axial direction of the spring. A technique for directing the spring force exactly within the axis of the spring could not prevail. Nowadays there is a tendency to increase the load capacity of the load arm with regard to advantageous technological aspects in the textile industry, the use of synthetic fiber mixtures is still increasing and the take-off speed will continue to be increased in order to work even more efficiently, and so on In order to achieve the best possible quality, the disadvantages of the known load arms increase.

Even if the deviations obtained by the springs could be kept in a very small range, the second disadvantage, namely the effect of disturbing the balance, still remains. This disturbing effect occurs under the influence of the curvature in a compression spring and due to the deviation from the axis of the compression spring, so that there is an angular deviation of the loading arm A, namely due to these deviations, so that the function peculiar to the swinging arm, namely that Alignment of the axis of the driven roller R parallel to the axis of rotation of the driving part is disturbed. This disadvantageous effect can be seen from the measurement results shown in FIGS. 6 and 7. This interference effect is explained with reference to FIGS. 22-24. From the front view in FIG. 22 it can be seen that the usual loading arm is loaded by a helical spring 23 which is supported with its upper end at the point 25 of a housing 21, while the lower end of the spring is supported at the point 26 of the loading arm 22 is. The transversely extending driven rollers 24 and 24 'are supported in the middle by the loading arm 22. The two roles mentioned lie on the driving part D. For this reason, the horizontal of the pressure contact surface of the spring 23 at point 26 is directed by the type of contact between the driving surface D and the driven rollers 24, 24 '. The design of the loading arm is influenced by a wide variety of factors, including the horizontal of the pressing surface of the spring 23 and the deviations of the spring 23 when the loading arm 22 is working, and by the deflection angle © s from the longitudinal axis of the spring 23, namely by the displacement of the pressure point P from the guide arm 22 with respect to the longitudinal axis ZZ ', which extends through the pressure point P, so that a vector Pi acts on the loading arm.

The vector Pi has a deflection angle A © s with respect to the vertical axis ZZ 'of the loading arm. Through this relationship, a force E was generated by the rollers 24 and 24 ', which acts in the direction of their axis of rotation XX', this force E being a force component which is directed against the return direction of the guide arm.

The magnitude of the force E, as shown in the vector diagram in FIG. 23, results from the following formula

E = PI sin A © s ... (5)

The deflection torque Ms, which is a moment in the deflection direction, which acts on the point P of the guide arm 22 and is generated by a pressure acting on the guide arm 22, results from the following formula:

Ms = s P sin A 0 s ... (6)

24, the loading arm 22 is deflected by the deflection by the angle der © with respect to the axis YY ', the latter axis extending through the pivot point of the arm 22. From the formula (4) it follows that the restoring torque Mr, which is generated in the center Q of the driven rollers 24, 24 ', is given by the following formula:

Mr = 21 Vo sin ô 0 ... (7)

The two types of torque, namely the deflection torque Ms and the restoring torque Mr have different directions and act simultaneously on the load arm O Qi in points P and Q. For this reason, the load arm OQ always remains in a position in which the two torques are balanced . This results from the following formula:

Ms = Mr ... (8)

It can be seen from the top view in FIG. 24 that the loading arm has two rotatable rollers lying on both sides and that equally large forces Ti and T2 occur on the opposite sides. This leads to the following derivation:

21V sin ô © = S Pi sin A © s

• S Pi sm ô © = sm s

21 V

© = -A_ s} n -1 sin A © s] ... (9)

\ 1V 1

From the formula (9) it is evident that there is a necessary and sufficient relationship for © = O, so that AÖs = O. This results if the pressure vector does not coincide with the ZZ 'axis (see FIG. 22), so that it does not return to the Q position. The relationship À 0s = O applies theoretically when the load arm is in its normal position, where XX '// xx' // YY '. This relationship means nothing more than the complete parallelism of the axis of rotation xx 'of the driven rollers with respect to the axis XX' of the driving floor D. This proves that the self-aligning properties of the top rollers with respect to the driving roller D are very imperfect when the load is swinging. In order to obtain a better alignment of the device, as is required in the textile factory, the allowable deflection range should be within 0.3 mm, as can be seen from FIGS. 6 and 7. It is necessary here that

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Reduce or eliminate distractions of the pressed body or component. However, it can be seen from the inspection curves that even if the technology is available for this, it is impossible to always stay within the permitted ranges shown in FIGS. 6 and 7 for quantities of tens of thousands or hundreds of thousands. 6 and 7 it can thus be seen that even with a high-quality production of the loading arm there can be no complete satisfaction with regard to the quality achieved and the mode of operation. The load arms used in textile factories are the key to achieving a press area that determines the quality of the spun yarn and performance. For this reason, it is very important to maintain and maintain the parallelism of the driven rollers R with respect to the driving base roller D.

The present invention aims to provide a device with which the aforementioned disadvantages can be avoided. It is assumed here that the peculiar deviations that occur during pressing are the main cause of the difficulties that arise. A rolling component is now to be arranged between the deflecting spring and the loading arm in order to isolate these components from one another. The rolling component has the task of eliminating the deflection vector and only transferring the necessary pressure vector directly to the vertical axis ZZ ', so that full use is made of the self-aligning principle and also of the known oscillating arrangement of the arm.

The loading arm can be arranged in a multiple arrangement in rows within a base body, wherein these loading arms can act as a single loading arm and can be arranged in a stretching section or withdrawal section. The load arm can be implemented in various embodiments and is also suitable for mass production. With this low load, great rationalizations and simplifications in the manufacture of textile products can be achieved.

If such an inventive device according to claim 1 is used in a spinning machine, the great improvement in the parallel holding of the axes of a bottom roller and a top roller creates the prerequisite for obtaining a high yarn quality. This improved yarn quality not only manifests itself in the improved quality of a textile product, but also increases the performance and productivity in spinning and also reduces errors and interruptions in the yarn, and higher outputs can also be achieved in a subsequent second process step. If e.g. For example, if a combed yarn is used, there is a great improvement in its preparation for weaving and in the weaving process itself, as shown in FIG. 47. This is because the quality requirements for this material will increase separately in relation to the improvement in manufacturing facilities due to the wide range of uses of the yarns obtained. These requirements can hardly be satisfied with the existing level of parallelism, as is the case with the existing load arms (see FIGS. 6 and 7). However, this does not mean that the requirements for the load arms in a spinning machine are not yet at an end. One of the problems to be mentioned is the increase in pressure, secondly the constant quality, thirdly the pleasant way of working and fourthly the lack of maintenance. Even with the most modern design of a loading arm, the disadvantages mentioned occur.

It was mentioned that, in addition to other things, the parallelism of the top roller with respect to the base roller is the greatest difficulty with the known loading arms. Needless to say, the parallelism of the top roller has a direct influence on the performance of the stretch section, so that one of the main factors in achieving the yarn quality can be seen. This improvement will result in a result that will elevate textile technology to a higher level. In short, this means that the invention enables all the top rollers present in the spindles of a spinning machine to work in such a way that the deviation from the parallelism of these top rollers (where there is no yarn unevenness) is within the allowable range of deflection. For this reason, the invention is important.

The drawing shows several exemplary embodiments of known load arms and several exemplary embodiments of the subject matter of the invention. Show it:

1 is a side view of a conventional, adjustable loading arm,

2 is a top view of the loading arm of FIG. 1; FIG. 3 is a graph showing the variations of a self-aligning device in which the arm of FIGS. 1 and 2 has been used;

4 shows a conventional oscillating load arm in plan view,

5 the arm of FIG. 4 in side view,

6 is a graphical representation of the frequency distribution of the parallelism in rear head rolls of a conventional device,

7 is a graphical representation of the frequency distribution of the parallelism of front head rollers,

8 and 9 a usual fixed load arm, one with a leaf spring and the other time with a helical compression spring, in vertical section,

10, 11 and 12 a customary adjustable loading arm, in a diagrammatic representation, as well as in section and in top view,

13-16 specific embodiments of individual parts of a customary adjustable load arm,

7 and 18 is a plan view of two different embodiments of known loading arms, for explaining the self-aligning effect,

19 is an illustration for explaining the above-mentioned effect,

20 and 21 two schematic representations of a conventional arrangement of a loading arm,

22-24 representations for explaining the existing problems, in front view and top view,

25-27 show two different embodiments of the subject of the invention each in a view and a side view,

28-46 show further embodiments of the subject matter of the invention, and

Fig. 47 is a table from which the percentage advantages occur in different applications.

The exemplary embodiments of the subject matter of the invention are now explained below.

25-27 shows the basic concept of the invention, which is described below.

1. The formation of the support point O for the pivoting movement of the loading arm A at the rear end comes from a device that works with a pivotable support, so z. B. of Fig. 4, with the spherical and thus spherical storage.

2. At the lower end of a compression spring S there is a rolling element. There is a bottom cap HB. In the event that a helical compression spring is used, the cap has

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a U-shape in cross-section, but with right-angled flanges protruding from the two legs. This cap receives the rolling element (rolling element). This rolling element can, for. B. have a ball K or a cylindrical roller or such a shape as in a needle bearing. The inner roof surface X3X3 'from the bottom of the cap is such that with respect to the upper surface X5X5' of the loading arm while working with the device there is the following relationship: XsXs'HXsXs'.

3. In a predetermined position of the upper surface of the loading arm, opposite to a pressing body, there is a surface section X2X2 'which forms a narrow guide surface and is used for the purpose of rolling.

4. Even if the measures listed under 2 and 3 are provided in reverse order, the function is exactly the same, with a few exceptions.

5. The compression spring S is usually in the form of a helical compression spring. The ends of the spring S offset by 90 degrees with respect to its longitudinal axis and the parallelism of the two end faces of this spring must be strictly observed in accordance with the regulations of the Japanese industrial standards. Although some discrepancies do occur, there is nothing if the discrepancy is within the acceptable range of Japanese industry standards. When the spring S is installed, its upper surface is fitted vertically onto a projection 25, this projection 25 being seated at a predetermined position on the ceiling of the housing for the loading arm. The inner surface X3X3 'of the bottom cap HB, which is located on the lower surface of the compression spring S, can have an almost horizontal position. The bottom cap HB is combined with the compression spring S in such a way that the play between the spring and the cap is kept as small as possible, and at the same time the cap is arranged in relation to the housing B for the loading arm in such a way that the play between the diameter (or width) d of the bottom cap HP and the width i of the housing is also as small as possible. This ensures that the vertical axis of the compression spring S approximately coincides with the reference axis ZZ 'of the housing. Such a structure ensures that the compression spring S remains upright at the predetermined location on the surface XsXs' of the housing B, so that the risk of spring deflection, that is to say the spring buckling, is greatly reduced, so that the axis of the spring essentially coincides with the central axis of the housing B, whereby the pressure exerted by the spring acts exactly vertically. Therefore, the surface X3X3 'of the bottom cap HB maintains the state XsXs'l IX3X3', so that the pressure of the spring element S in the cap HB has the pressure of the spring S on the surface X2X2 'of the loading arm B in the correct direction is transmitted, so that only the required correct pressure is achieved and transmission of a significant deflection of the compression spring S is eliminated.

6. On the other hand, the self-alignment of the driven roller R, which is driven by the body D, is achieved in accordance with the type mentioned at the outset, namely by the self-aligning oscillating movement of the loading arm A around the articulation point O. It follows that the rolling element A the contact points 27, 28 between the surfaces X2X2 'and X3X3' is prevented from rolling at all or only very slightly. The rolling resistance is therefore extremely low. In this way, an ideal construction can be achieved which has an oscillating load arm which can oscillate independently of the pressure and without any significant resistance. Despite the parallel position of the upper and lower rolling surfaces X3X3 'and X2X2', between which the rolling element is located, it cannot be entirely avoided in practice that a slight oblique position is established between these two surfaces.

In the known devices, however, there are already means for compensating, so that this inclined position only has a very small extent, so that no slippage occurs on the rolling surfaces of the rolling element, since this resistance to slipping also increases due to the pressure transmitted. In short, this means the essential advantage of the present device and can be seen in the fact that the arrangement of the rolling element between the bottom surface X3X3 'of the pressing body and the upper surface X2X2' of the loading arm on the pressed side effects three different functions, namely a rolling function, furthermore the function of pressure transmission and the function of eliminating a deflected pressure vector, that is to say preventing a pressure component from the pressing body between the rolling surfaces, which are formed by the upper and lower, mutually parallel surfaces, between which the rolling element is located. The invention thus shows a new way of keeping the resistance that occurs when the oscillating movement of the loading arm self-aligning to zero, even at high pressure and with full development of the pendulum ability. A support for rolling under pressure is thus formed in response to the restoring torque that occurs automatically on the loading arm side with responsiveness even under a large load, the pure pressure, which does not interfere with the pendulum function of the loading arm A, exactly on that Head role R is transferred.

7. In the fume cupboard area of a textile machine, the swivel angle of an extremely large deflection with the existing loading arm is not necessary, and in some cases unnecessary swinging is harmful. Due to the demand in recent years to use large and heavy-duty loading arms, the excessive swivel angle has a close correlation with the reduction in the parallelism of the top roller R.

The principle of the self-aligning function of the pendulum system was examined, which was previously considered ideal with the loading arm, and a new way has now been found to use this loading arm in the most efficient way possible. The causes of the reduction in parallelism that exist in the known devices were also investigated, and it was found that a precisely limited range for increasing the stability required for the advantageous use of the essential features in the known devices the swivel angle of the loading arm A is present, and that the limited amount of the effective deflection of the loading arm goes hand in hand with the amount of the accumulating errors, which errors occur in the manufacture of the loading arm, so that the deflection of the loading arm by a special means allowable minimum amount is limited. With the invention, a construction can be created in which a perfect self-resetting function is achieved by using measures which insist on the aforementioned various concepts and make reasonable use of the principle of self-alignment in the pendulum system.

It is evident from the above that the invention was created through long tests and extensive experience with the properties of the existing typical load arms. The conclusion is that the principle of self-alignment in known pendulum systems is theoretically very precise and that excellent and stable functions suitable for the load arm occur if this principle is applied correctly. The reason why the parallelism of the head roller R is disturbed can be seen in the fact that errors in the loading arm prevent or make the performance of the head roller more difficult. It can be concluded that, even s

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if the pressure-exerting organs exert their pressure essentially directly, the correct self-alignment that is inherent in the loading arm can be achieved if some measures are taken to prevent the influence of the direct direction. The present invention 5 therefore uses a method in which the self-alignment of the known loading arms is no longer used, but instead a rolling element is arranged between the loading arm A and the pressing body S.

The invention will now be described with reference to FIGS. 28 to 46 10.

28-39 show the relationship between the bottom cap HB, which holds the rolling element K, and the housing B for the load arm, and further show different positions of the contact points 27, 28 between the rolling element 15 per K and the bottom cap HB and arm A.

FIG. 28 shows a front view of a device provided with a loading arm. 29 shows a side view of part of the device. In FIG. 28 there is a recess M on an area of the loading arm A, against which the rolling element (ball) is pressed. The shape of the recess M is such that

if viewed from the side according to FIG. 29, there is a curved channel which has the radius R 'which is somewhat larger than the radius R of the ball K. If one looks at the recess M in the view according to FIG. 28 , the recess has the radius R, which is equal to the radius R of the sphere K, the center of which is offset by the amount Àô, so that a flat surface is formed over the distance Aô.

Since the ball K rolls within the recess M, a horizontal swinging of the loading arm A is achieved in the area of this area Aô, which makes it possible to control the pivoting angle of the loading arm A. The ball K lying inside the bottom cap HB has some play so that the rolling of the ball K is not hindered. In the side view according to FIG. 29, the cross section of the recess M is such that no horizontal displacement of the ball K is made possible, so that the contact point 27 is retained on the reference axis ZZ '.

On the other hand, the bottom cap HB is fitted into the housing B for 40 the load arm, and has a height h. This ensures that the tendency to deflect or buckle the compression spring S is compensated.

Although there is no control of the horizontal displacement of the bottom cap HB from the view according to FIG. 29 in this device, no problem arises in practice since the ball K is under control through the depression M in the loading arm A.

35 and 36 show an embodiment in which the cover plate of the arm A is provided with a rectangular recess M 'which serves as a running surface for the ball K. In this case, the amount of rolling displacement of the ball K is controlled by the dimension of the longer side of the rectangular recess, as can be seen from the front view in FIG. 35. From the side view according to FIG. 36 it can be seen that the rolling surface for the ball K has a recess width b and that the ball K touches the running point on two edges 27 and 27 ', as a result of which the same working state as in the illustration follows Fig. 28 sets. Although the bottom cap HB is freely movable in the housing B for the 60 loading arm, and only because of its plate thickness, this is sufficient if the accuracy of the compression spring S is good.

37-39 show a further exemplary embodiment of a part of the subject matter of the invention. From the front view 65, according to FIG. 37, it can be seen that elevations 29, 29 'are present at certain points on the outer surfaces of the loading arm A which are opposite one another and which are used for

Control the swing movement. This idea is similar to the control pins described with reference to Figures 13-16. As a result of this measure, an oscillation play Aô with respect to the inner dimension of the housing A is now released for the loading arm.

This relationship corresponds to the distance Aô in Fig. 28. Deviating from this, it is now no longer necessary to provide a recess in the upper surface of the arm A. The other structure is as in the example of FIGS. 28-31. However, there is an additional facility

elevations 30, 30 ', 31, 31' are arranged on the opposite inner surfaces of the housing B in order to encompass the outer lateral surface of the bottom cap HB, as can be seen from the top view in FIG. 39. This controls the movement of the bottom cap HB so that it can only move exactly in the direction of the compression spring, i. H. in the direction of the central axis of the compression spring, without deviations in other directions. Such a structure can be used without changes in the embodiments according to FIGS. 28-36. 40-43 two other embodiments of the rolling components are shown. In these examples, a roller is used as the rolling element.

FIG. 40 shows a front view, FIG. 41 shows a side view in a diagrammatic representation, and FIG. 42 also shows a diagrammatic representation of an expanded example. A construction can be seen from the side view in Fig. 43, in which a leaf spring S 'is used and the rolling element is also a roller.

FIGS. 44, 45 show a further exemplary embodiment, which is similar to the example according to FIGS. 40-43, but with the roller representing the rolling element being arranged differently. In contrast to the example according to FIG. 40, in which the roller is arranged on the bottom cap HB, in the example according to FIGS. 44, 45 the roller is arranged on the upper plate part of the arm A. Both examples according to FIGS. 40-45 have the advantage that the rolling element K can be stabilized by grasping the axis of rotation of the roller, and therefore the pivoting of the arm A is also stabilized. In some cases, however, such a construction can become too complicated and, if this construction is made simpler, slippage can occur. A small amount of slip does not matter too much, but this construction is primarily suitable for those cases where stabilization is the most important thing.

An exemplary embodiment can be seen from FIG. 46, which can be regarded as a universal construction. This device can be arranged on the various existing rollers (front roller, second roller, third roller, etc.) in the take-off section of a textile machine.

46 that the pivot axis O for the loading arm A is present at the lower end of the housing B. The other end of the loading arm A is provided with a handle 43 which is received by the lower edge of a rectangular recess 34 in the housing for the arm. The axis G of the top roller R is held in a lower U-shaped groove in the arm A. The opposite ends of the helical compression spring S are provided with a head cap 32 and a bottom cap 31 in order to form mutually parallel surfaces which are perpendicular to the central axis of the spring S.

The upper surface of the loading arm is provided with a running surface for the rolling element K. Usually, the center of the rolling element K lies on the reference axis ZZ ', so that the rolling element cannot move forward or backward relative to the arm A, whereas there is a limited evasive range in the pivoting direction. The remaining structure corresponds to that according to FIGS. 28 to 39. In the bottom cap 31 there is more than the upper half of the rolling element

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pers K and the upper point of the rolling element are under pressure in contact with the ceiling surface of the bottom cap 31.

The bottom cap 31 and the top cap 32 have very little play with the compression spring S on their inner lateral surface. Furthermore, these components 31 and 32 also have only a slight play with respect to the housing B with their outer lateral surface, so that the parts 31 and 32 only are displaceable in the printing direction. The upper part 36 of the housing B forms a fastening part for optionally fastening the device to a main body 42 and also serves to receive an adjusting screw 35 with which the pressure of the spring S can be adjusted.

In this exemplary embodiment, a reference plate 41 is provided for setting the compression spring. However, this is only one exemplary embodiment; other methods can also be used. So z. B. there may also be a stepwise Ver-s position of a cam disc present at the head of the device; however, a combination of a linkage with a cam disc can also be used. The illustrated pins 38 and 38 'are further an example for uniting the upper and lower components 36 and 37 of the housing io B. It is of course also possible to make these components in one piece with the housing B.

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Claims (7)

617 230 PATENT CLAIMS 1. Device for yarn stretching in textile machines, with an oscillating, self-aligning loading arm, with a housing (B) and a swivel member (O), the loading arm (A) having one end around the swivel member (O) of the housing (B) several axes (XX, YY, ZZ) is movable, with driven, rotatable rollers (R) at the other end of the loading arm (A), with a drive body (D) for driving the driven rollers (R), with a pressing member for the Low stress (A), wherein the pressing member is between the two ends of the loading arm and holds the rollers (R) in engagement with the drive body, characterized in that the pressing member has a cap (HB) with a U-shaped cross-sectional profile, which is located at the bottom End of the case (B) and within the housing can perform a movement directed vertically against the upper surface (X2-X2O of the loading arm) that there is a rolling element (K) inside the housing (B) which is between the bottom (X3-X3 ') the cap (HB) and the upper surface (X2-X2 ') of the loading arm (A) and between its two ends in contact with the loading arm (A) is that the width of the rolling element (K) is less than the inside diameter of the reverse lying U-shaped cap (HB) is for free rolling movement of the rolling element (K) within the cap (HB), and that a spring (S) is inside the housing (B) and above the cap (HB), which spring that Aim to push the cap (HB) vertically with respect to the upper surface (X2-X2 ') of the loading arm against the rolling element (K). 2. Device according to claim 1, characterized in that the rolling body (K) is designed as a ball. 3. Device according to claim 1, characterized in that the rolling body (K) is designed as a cylinder. 4. Device according to claim 1, characterized in that the rolling element is designed as a spherical roller. 5. Device according to claim 1, characterized in that the cap is provided with organs through which the effective rolling area for the rolling element (K) is determined. 6. Device according to claim 1, characterized in that the upper surface (X2-X2 ') of the loading arm (A) has a recess (M) which serves to control the range of motion of the rolling body (K). 7. Device according to claim 1, characterized in that the upper surface (X2-X2O of the loading arm (A) has an opening (M ') which serves to control the range of motion of the rolling body (K).