WO2018108989A1

WO2018108989A1 - Friction feeder

Info

Publication number: WO2018108989A1
Application number: PCT/EP2017/082580
Authority: WO
Inventors: Dietmar Tränkle
Original assignee: Sipra
Priority date: 2016-12-16
Filing date: 2017-12-13
Publication date: 2018-06-21
Also published as: DE102016015018A1; CN110073043A; EP3555352A1; TW201825730A; JP2020502382A

Abstract

The invention relates to a friction feeder for receiving a plurality of threads from one or more corresponding thread delivery devices and feeding at least one of the threads to a thread-processing point of a knitting machine. At least two rollers arranged parallel to each other receive the threads and transport the threads in that the threads are carried along by the rollers by friction on the roller surfaces. A deflecting element is used to adjust the carry-along force applied by the rollers to at least one of the threads, wherein the rollers are arranged in such a way that the threads can be wrapped around both together at least once. The deflecting element can be set in such a way that the deflecting element deflects the thread or threads in a section of the course of the thread wrap between the rollers in such a way that the angle of wrap of the thread or threads around the rollers and thus the contact length of the thread or threads with the roller surfaces can be increased or decreased.

Description

Friktionsfournisseur

description

The invention relates to a friction feeder of a multi-filament knitting machine, in particular a circular knitting machine with ringing device.

FIG. 1 shows a schematic side view of the thread guide at a single knitting point in such a conventional circular knitting machine with ringing device 5.

The thread to be processed is the knitting point 6 via a thread monitor

3 and a Fadenleitring 4 supplied from a feeder 2, which subtracts the yarn via a thread feed 1 from a yarn package and thereby additionally ensures that a suitable yarn tension is maintained. The required thread tension initially depends on the thread material used. In jacquard knitting machines, moreover, the decrease of the thread at the knitting point varies, which causes variations in the thread tension. The feeder has to compensate for these fluctuations as much as possible.

Conventional friction feeders include a drive roller, which also serves as a storage and transport role for the thread. This takes up the yarn fed from a yarn package and is wrapped by this one or more times. Driven by the active rotation of the roller, the thread is then fed to the knitting point. The transmission of the driving force of the roller on the thread takes place by friction on the roller surface. The speed of the thread is thus at most as large as the tangential speed of the transport roller with a friction feeder. Positive, slip-free yarn feeding is when the yarn speed is equal to the tangential velocity. The required friction on the roller surface is first ensured by the choice of a suitable friction material as friction lining for the roller surface. The friction causing the thread transport then depends on the friction coefficients of the friction lining material and the thread material and on the wrap angle of the thread around the transport roller. The wrapping angle can be adjusted by the number of wraps of the thread around the transport roller and determines the contact surface or length of contact of the thread with the roller surface (a wrap angle of 360 ° corresponds to a full loop).

If only one thread is to be processed in a knitting machine at a knitting point, usually a positive, slip-free thread supply with the thread tension that is as constant as possible is desired. The surface material of the transport roller and the wrap angle can then be adjusted so that the resulting frictional force can ensure the desired positive thread feed.

In knitting machines that process more than one thread at their respective knitting points, such as circular knitting machines with a ring function, making such adjustments is more complicated. Here, the feeder several threads are supplied, of which, however, only one is transported to the knitting point at any time. The unused threads are severed in the thread running direction behind the feeder in a ringing device and kept there clamped. The ringing device is controlled so that the required in each case for the striped pattern thread is released and transported to the knitting point, while the transport of the previous thread is interrupted by cutting and disconnecting. The transport role of Friktionsfournisseurs is thus wrapped in several threads here, of which, however, only one is to be transported to the knitting point. The other threads are clamped behind the feeder in the ring device and should not be tightened, which ultimately means that the sliding friction forces exerted by the rotating transport roller on these threads should not just overcome the respective thread resistance. If these threads are still transported anyway, they would be wound on the transport rollers.

A Friktionsfournisseer satisfying these requirements should thus allow a variable adaptation of the friction forces to different thread materials in a manner that allows both a uniform transport of each thread when it is being processed at the knitting point, as well as a sliding past the roller surface on the unneeded threads ,

In feeder of the patent application DE 35 06 552 A1 are used in addition to the two threads leading transport role different adjustable yarn guide. Each of the two threads then runs in one or more turns over two of the yarn guides as well as over part of the transport roller. Depending on the positioning of the yarn guides, the wrap angle and with it the contact length between the roll surface and the thread can be adjusted so that the thread is taken along by the friction on the roll surfaces or that the rotating roll surface slides past the thread due to a lack of sufficient frictional force.

The yarn guide of DE 35 06 552 A1 act as deflection that take the thread from each other or from the transport roller, deflect it and send it back to the transport roller or on the other thread guide. Since the thread windings continue to run around the transport roller around, albeit in a partially extended by the thread guide bow, the deflection angles occurring at the thread guides are large. This has the consequence that counteract the thread guide caused by the frictional forces arising in the deflections of the transferred from the transport roller surface on the thread feed force, which has a negative effect not only on the effectiveness of the yarn transport itself but also on the Maintaining a uniform thread tension by the feeder. Thread tension irregularities, in turn, can cause inaccuracies or errors in knitting processing which, in turn, result in defects in the fabric being processed. Furthermore, the setting of the yarn transport in DE 35 06 552 A1 due to the many adjustable yarn guide whose relative positioning is critical to each other, complicated for the operator.

We are therefore looking for a solution with which the angles of wrap of the various threads with the transport roller (s) or the contact lengths of the threads with the transport roller surface can be switched in or out so flexibly that the respective thread to be processed is reliably transported with a uniform thread tension. while re-shooting and winding the other, clamped threads is avoided. In addition, the adjustment of the friction guide with regard to the desired wrap angles should be as uncomplicated and quick as possible.

The Friktionsfournisseur defined in claim 1 solves the above problem in that the thread once or twice wrapped around two parallel transport rollers and a deflection deflects the thread in a portion of the thread path between the transport rollers. The dependent claims describe preferred embodiments of the invention.

If one of the deflection elements is positioned in such a way that it deflects the respective thread outwards from the inside of its wraps, this reduces the wrap angle. The contact length of thread and roller surfaces and thus the force exerted on the thread friction force are reduced. If the thread tension is released after the thread is clamped in the ringing device, the roller surfaces slide past the thread. By a deflection of the thread from the outside of the wraps from the inside, however, the wrap angle is increased. The extension of the con- Cycle of thread and friction lining on the roller surface leads to an increased frictional force and thus to an improved thread transport. This optional arrangement of the deflecting elements inside or outside all or even some of the thread wraps makes it possible in particular to tune the friction feeder to very different thread materials, ie those having very different coefficients of friction, without requiring a complicated replacement of a friction lining of the transport roller. The operation of a knitting machine equipped with such a friction feeder with changing thread materials is thereby considerably simplified.

In a knitting machine with ringing device, the positions of the

Deflection elements for the various threads are also controlled in operation so that the wrap angle is sufficiently increased for the thread to be processed, while the wrap angle for the unneeded threads are kept sufficiently small. The position control can be done continuously or in discrete stages. Optimally, the position control takes place automatically and is coordinated with the control of the ringing device.

The result of the positioning of the deflecting elements in the thread path between the transport rollers is that each of the deflecting elements is fed by a transport roller on one side of the deflecting element, in order then to be passed on to the second transport roller on the other side of the deflecting element. In this way, the deflection angles occurring at the deflecting elements are kept small. The smaller deflection angles result in lower frictional disturbances and lead to an improved maintenance of the feed force exerted by the feeder on the thread with uniform thread tension. This advantageous effect can be further improved by the deflecting elements are designed as co-rotating roles. In terms of maintaining a uniform yarn tension Suppliers often contain resilient thread guide elements, of which, for example, fluctuations in yarn consumption can be compensated as instantaneous. This function can be completely or partially filled by the deflecting elements in the friction feeder of the present invention, if they are each arranged resiliently, for example by being held by resilient brackets rotatable about a pivot.

The transport rollers may have the same diameter or different diameters. It is also conceivable that they have sections of different diameters, wherein the sections each lead different threads. They can be operated at the same speed or at different speeds.

Also particularly advantageous is a horizontal arrangement of the transport rollers, either above or next to each other. A lying arrangement has the advantage that the wraps of the threads on the rollers can not fall down or slide on the roller. In this way, the threads run safely next to each other without being confused.

Finally, the friction feeder of the present invention can be applied to various types of knitting machines that process a plurality of threads under a certain tension. These are primarily circular knitting machines with ringing device, which work with or without jacquard technology. Especially with knitting machines with jacquard technique, the positive effect of the present invention on the thread tension is particularly advantageous. However, it is also conceivable to use the feeder in other knitting, knitting, weaving or sewing machines with multiple threads.

The invention will be explained in more detail with reference to the drawings. Showing: Figure 1 is a schematic view of the structure of a conventional circular knitting machine with ring function, showing the yarn path from a yarn package on the conventional Friktionsfournisseur to knitting;

Figure 2 is a perspective view of a Friktions- supplier according to the invention with mounted in a perforated strip deflecting elements and for reasons of clarity with only one transported thread;

Figure 3 is a side view of the Friktionsfournisseurs of Figure 2;

Figure 4 is a perspective view of another Friktionsfournisseurs invention with attached to flexible hangers deflecting elements and with two transported threads;

Figure 5 is a perspective view of a yarn guide variant with minimum Gesamtumschlingungswinkel with two wraps around the transport rollers;

Figure 6 is a schematic representation of the yarn guide variant with minimal Gesamtumschlingungswinkel from Figure 5;

Figure 7 is a schematic representation of a yarn guide variant with average Gesamtumschlingungswinkel with two wraps around the feed rollers;

Figure 8 is a perspective view of a yarn guide variant with average Gesamtumschlingungswinkel without deflection;

9 is a perspective view of a yarn guide variant with maximum Gesamtumschlingungswinkel in two wraps around the transport rollers.

FIG. 10 a schematic representation of the thread guiding variant with maximum total wrap angle from FIG. 9.

Figure 1 1 is a perspective view of the yarn guide variants of Figures 5, 7 and 9 in a common view; Figure 12 is a perspective view of a yarn guide variant with two transported threads which wrap around the transport rollers twice;

In a circular knitting machine with ringing device, a number of threads, for example four or six threads, run through each of which, only one of which is controlled by the thread selection on the ringing device at a time, while the others are disconnected. Figures 2 and 3, in which for the purpose of illustrating the thread pattern in Friktionsfournisse invention only a thread passes through the feeder show so far only a partial aspect of an embodiment of a Friktionsfournisseur invention, the shown in Figure 1 conventional Friktionsfournisseur in a circular knitting machine with ring function replaced.

The friction feeder according to the invention has two transport rollers 1 1, 12, which are lying, i. with horizontal axes, held parallel to each other. Preferably, the transport rollers are arranged one above the other, whereby access to them is simplified; but it is also possible a parallel arrangement next to each other or at an angle to each other.

The transport rollers have the same roller diameter and are both driven at the same speed. However, there are also transport rollers of different diameters conceivable that may be driven at different speeds.

The transport rollers each have corresponding subdivisions for the respective threads. The more threads that are to be guided, the more subdivisions have the correspondingly longer in the axial direction of transport rollers. In particular, therefore, the transport rollers of a friction conveyor according to the invention in a circular knitting machine with ringing device in the axial direction are longer than the transport rollers shown in FIGS. 2 and 3. The threads (in Figures 2 and 3 for illustrative purposes, only one thread) Then run each of their yarn spools successively on both transport rollers, before they continue to lead to ringing device. They can wrap the transport rollers one or more times.

The Friktionsfournisseur in Figures 2 and 3 provides at least one deflecting element 13, which deflects a yarn to be transported in its course between the two transport rollers 1 1, 12. In this case, the deflecting element 13 can either be arranged so that it the yarn course inwards, i. in the direction of the interior of a wrap of both transport rollers, deflects or deflects it outwards and thus increases or reduces the wrap angle of the thread around the transport rollers. The deflecting element 13 can be arranged to be adjustable in particular in the direction perpendicular to the connection of the roller centers and the roller axes, for example by attachment to a perforated strip 15 as shown in FIGS. 2 and 3. The perforated strip 15 allows differently strong deflections of the thread inwards or outwards.

For the purpose of reducing friction, the deflecting element 13 is preferably itself designed as an at least passively rotating roller. If the transport rollers are looped several times by the corresponding thread, the thread can be guided around the deflecting element so that only one, several or all of the wrappings are deflected. If more than two threads are processed, then a plurality of threads are guided side by side on the subdivisions of the transport rollers. It can also be provided a plurality of deflection, for example, one for each thread (or two per thread to facilitate the deflection of each thread either inward and outward). In the case of multiple threads and deflecting the adjustable attachment of the deflecting elements can continue to be ensured as in the example of Figures 2 and 3 by one or more perforated strips 15; other Mounting variants that allow more of the deflecting elements in the same position, however, are conceivable and possibly more practicable.

Since in a circular knitting machine with ringing device a certain re-shooting of a thread just clamped to the ring means is unavoidable, a compensating element 20 (see FIG. 3) is generally provided which can pick up or store the subsequent thread until the positive thread transport by means of appropriate Conversion of the deflection has come to a standstill. Such a compensating element can be realized, for example, by a laterally abutting the spring element spring that is slightly biased against the thread and this deflects at a suddenly decreasing thread tension to the outside and keeps under tension. In this way, the unwanted spooling of the thread around the transport rollers following excessive re-shooting can be prevented.

FIG. 4 shows a variant with deflection elements 13 ', 14' held on brackets 17, 18 via a pivot pin 16. Here, two of the upper transport roller supplied threads are processed; However, this variant can be applied by appropriate broadening of the transport rollers 1 1, 12, the deflecting elements 13 ', 14' and the ironing pin 16 to any number of threads to be processed. Preferably, the stirrups 17, 18 are at least slightly resilient, so that the deflecting elements 13 ', 14' held against them can yield slightly to the tension of the deflected thread, which has an advantageous effect on the uniformity of the thread tension.

It can be seen in the figure that the course of the thread to be processed is deflected inwards by the deflection element 13 '. The wrap angle of the thread and with it the contact length of the thread with the friction linings on the roller surfaces are thereby increased. The friction force transmitted by the friction linings is increased and the positive yarn transport is supported. On the other hand, the thread course of the other, currently not to be processed thread from the deflecting element 14 'deflected to the outside. The wrap angle of the thread and with it the contact length of the thread with the friction linings on the roller surfaces are thereby reduced, whereby less frictional force is transmitted. With a suitable setting, this ensures that the friction linings slide past this thread and do not continue to transport it positively.

The positioning of the deflecting elements 13 ', 14' by means of the stirrups 17, 18 can, in contrast to the perforated strip 15 of FIGS. 2 and 3, take place continuously. In addition, the control of the bracket 17, 18 can be automated, in particular in accordance with the control of the ringing device. When cutting and clamping the previously processed thread and entrainment of a previously clamped, from now on to be processed thread in the ring means the corresponding deflection 13 ', 14' then changed so that the positive transport of the previously processed thread by reducing the wrap angle and thus shortening the contact length is adjusted with the friction linings, while the wrap angle of the new thread to be processed and with this the contact length are extended, whereby the thread transport is resumed. Such coordinated control of the catch device and deflecting elements preferably takes place in a control device which can be embodied as part of the overall control of the knitting machine.

If the threads wrap around the transport rollers more than once, a deflecting element held within and outside the loop can be provided for each thread. By suitable coordinated control of the two deflecting elements, deflections of the respective thread to the outside to reduce the wrap angle (and shorten the contact length with the friction linings), ie also deflections, are then detected inside to increase the wrap angle (and lengthening the contact length) possible.

The attachment of the bracket 17, 18 on the pivot pin 16 is merely an exemplary mounting variant. It can also be provided several trunnions or wholly other other support options. Especially in the case that the straps are controlled in coordination with the ring device, the attachment and support must be designed so that an individual and automatic control of the strap is made possible.

FIGS. 5 to 10 show different variants of the guidance of a thread by corresponding adjustment of the deflecting elements in the friction feeder according to the invention in order to demonstrate the possibilities for controlling the transmission of the frictional force in the present invention. In the figures, the thread wraps around the transport rollers 1 1, 12 two times, and the deflecting element 13 is attached to a perforated strip 15. Figures 6, 7 and 10 show schematic views of the thread pattern, in which the thread pattern is subdivided into four different phases 1 to 4 for better understanding.

In the first variant depicted in FIGS. 5 and 6, the thread first passes past the upper transport roller 1 1 to the deflecting element 13 (phase 1) arranged at an outermost position a of the perforated strip 15, from which it reaches the lower transport roller 12 is diverted. It wraps around it at an angle of 135 ° (phase 2), before it is returned in the direction of the upper transport roller 1 1. This he wraps around again at an angle of 135 ° (phase 3). Once again via the deflection element 13 at the outermost position, it returns to the lower transport roller 12, which it wraps around at an angle of 45 ° (phase 4), before it is guided further in the direction of the knitting point:

FIG. 6: minimum total wrap angle Phase looped roll wrap angle

1 input - roll 1 1 0 °

2 rolls 12 135 °

3 roll 1 1 135 °

4 roll 12 - output 45 °

total 315 °

The total wrap angle on both transport rollers is 315 ° in this example. With two wraps and the two possible positions of the deflecting elements indicated in the figure, this is the minimum wrap angle.

FIG. 7 is a schematic view of a further variant with another thread guide over the deflection element with two wraps around the transport rollers. While one of these two wraps is deflected by the deflecting element 13 which in turn is arranged at an outermost position a, the other runs directly from one transport roller to the other. This results in a mean total wrap angle of 405 °:

If, in contrast to FIG. 7, both threads are guided without deflection from one transport roller to the other, the deflection element remains without function. This configuration is shown in FIG. This example corresponds to the yarn guide in a feeder with two transport rollers without deflecting elements between them. In the friction of the present invention this configuration remains as one of several possible setting variants. As Gesamtumschlingungswinkel results in this case 495 °.

Finally, FIGS. 9 and 10 show a corresponding example with a maximum overall wrap angle of 675 ° in the case of two wraps which are respectively deflected by the deflection element 13 arranged at an innermost position b:

Already these few examples show that the total wrap angle can be set over a considerable range in the friction feeder according to the invention. The adjustment parameters are primarily the number of deflected Fadenumschlingungen and the position of the or the deflection. The maximum Gesamtschliesungswinkel in Figure 9 of 675 ° is more than twice as high as the minimum angle of 315 ° in the example in Figure 5. Thus, the contact length of thread and friction linings and the force exerted on the thread friction force are much greater.

Finally, FIG. 11 illustrates, in a single illustration, the three possibilities of thread guidance considered above from one transporting roller 11 to the other transporting roller 12. The thread can be deflected outwards via the deflecting element 13 at the outermost position a to minimize the wrapping angle (Variant A), or be deflected inwards via the deflection element 13 at the innermost position b to maximize the wrap angle (variant B). When passing through the thread without deflection the Umlenkelennent 13 remains without function (variant C). For a better understanding, it should be noted that FIG. 11 with the three different thread guides in the execution and only one in the return direction does not represent a real configuration of the feeder but merely serves to jointly illustrate the various alternative thread guide variants.

FIG. 12 shows an example in which two threads are each guided twice over the same deflection element 13 'in such a way that their respective angles of wrap are minimized. That is, the thread guides correspond respectively to the variant shown in Figures 5 and 6. This setting is useful, for example, if both threads are made of the same material, for which it has been shown that the best way to ensure with reduced wrap angle is that the thread to be processed is reliably transported and the transport roller surface slides past the respective other thread. The example of FIG. 12 can be expanded to any number of threads, which are then transported by the same deflecting element or by different deflecting elements with identical or different thread guiding variants. If an individual deflecting element is provided for each thread and held accordingly (for example on individually controllable ironing), the thread guides can also be controlled synchronously with the control of the ringing device so that the wrap angle is increased for newly processed threads, while the wrap angle for a straight clamped thread is reduced. With two individual deflection elements per thread, the deflection control between deflection can vary outwards and inwards.

The illustrated in Figures 5 to 12 thread guides are only exemplary. By appropriate changes in position of the deflecting elements as well as by changing the number of wraps can be the range of possible total wrap angles is almost unlimited. As already shown in the examples, a thread in one of its wraps can be deflected by one deflecting element, while it is guided in another loop around another deflecting element (or none at all).

In the above examples, the operation of the friction feeder of the present invention will be described using examples of one and two processed threads. In fact, it is particularly suitable for use in circular knitting machines with ringing device, which each process more than two different threads at their knitting points. The operation of the feeder remains basically the same as in the examples described above.

Finally, the friction feeder of the present invention can also be used in other textile processing machines in which different threads are used, so that the sliding frictional force required for the respective threads can be set as flexibly as possible without expensive material exchange.

Claims

claims

1 . Friction feeder for receiving a plurality of yarns from one or more corresponding yarn feeding devices and feeding at least one of the yarns to a yarn processing station of a knitting machine, comprising at least two rollers (11, 12) arranged parallel to each other for picking up and transporting the yarns by passing the yarns from the rolls Friction be taken on the roll surfaces;

a drive device for rotating the transport rollers; and

a deflecting element (13) for adjusting the driving force exerted by the rollers on at least one of the threads;

wherein the rollers are arranged so that the threads can be looped around both at least once,

wherein the deflection element can be adjusted so that it deflects the thread or threads in a portion of the course of Fadenumschlingung between the rollers so that the or the wrap angle of the thread or threads can be selectively increased or decreased by the rollers.

2. Friktionsfournisseur according to claim 1,

wherein the or the angle of wrap of the thread or threads around the

Rolls by means of the deflecting element (13) can be continuously increased or decreased.

3. Friktionsfournisseur according to claim 1,

wherein the or the angle of wrap of the thread or threads around the

Rolls by means of the deflecting element (13) in discrete stages can be increased or decreased.

4. Friktionsfournisseur according to any one of the preceding claims, wherein the rollers (1 1, 12) are adapted to receive more than a common wrap of the threads, and the deflecting element (13) is formed so that it or the threads in one or redirects several of the wraps.

5. Friktionsfournisseur according to any one of the preceding claims, comprising

a plurality of deflection elements (13, 14), which are each assigned to one of the plurality of taken-up threads and with each of which the angle of wrap around the rollers can be increased or decreased independently of the other deflection elements.

6. Friction specialist according to one of the preceding claims,

wherein the one or more deflection elements (13, 14) are each formed as rotatable deflection rollers.

7. Friktionsfournisseur according to any one of the preceding claims,

wherein the one or more deflecting elements (13, 14) are each held resiliently.

8. Friktionsfournisseur according to any one of the preceding claims, further comprising

a pin (16) and

for each deflecting element (13, 14) a bracket (17, 18) which is mounted on one of its ends rotatably mounted on the pin and on the other holds the deflecting element.

9. Friction exporter according to one of the preceding claims, wherein the deflecting element or each of the deflecting elements (13, 14) can be adjusted such that it deflects the respective thread outwardly from the interior of the thread winding course and thus reduces the wrap angle around the rollers (1 1, 12), and / or can be adjusted so that it deflects the respective thread from the outside of the Fadenumschlingungsvehaufs inward and so increases the angle of wrap around the rollers.

10. Friktionsfournisseur according to claim 9,

wherein the settings of the deflecting element or each of the deflecting elements (13, 14) can be carried out automatically and during operation of the knitting machine.

1 1. Friction feeder according to one of the preceding claims,

wherein the rollers (1 1, 12) lying, side by side or one above the other, are arranged.

12. Friction specialist according to one of the preceding claims,

wherein the rollers (1 1, 12) have different diameters or sections with different diameters.

13. Friction specialist according to one of the preceding claims,

wherein one or all of the rollers (1 1, 12) each have roller sections of different diameters.

14. Friction exporter according to one of the preceding claims,

wherein the drive device only one of the rollers (1 1, 12) or all roles actively rotates.

15. Friktionsfournisseur according to any one of the preceding claims, further comprising a control device for adjusting the one or more deflection elements (13, 14).

16. Friction exporter according to one of the preceding claims,

wherein the knitting machine is a flat, circular or knitting machine with or without jacquard technique.