EP2049718A1

EP2049718A1 - Thread delivery device having a novel yarn sensor

Info

Publication number: EP2049718A1
Application number: EP06776696A
Authority: EP
Inventors: Richard Kaufmann; Michael Mixner; Walter Letzgus
Original assignee: Memminger IRO GmbH
Current assignee: Memminger IRO GmbH
Priority date: 2006-08-09
Filing date: 2006-08-09
Publication date: 2009-04-22
Anticipated expiration: 2026-08-09
Also published as: BRPI0621827A2; WO2008017319A1; BRPI0621827B1; TWI376439B; TW200809028A; EP2049718B1; CN101506421B; CN101506421A

Abstract

In a thread delivery device (1) which is improved with regard to its thread sensor, the thread sensor (18) and an associated thread guiding device (12) preferably form one structural unit which can be adjusted parallel to the rotational axis of the thread delivery wheel (3). A lever (19) or another element which is preferably arranged so as to stand upright belongs to the thread sensor (18). It therefore extends in a first transverse direction away from the thread. In a first embodiment, it is movable in a second transverse direction (pivoting direction), while it is mounted such that it can be displaced longitudinally in a second embodiment. Movement pulses which are caused by the running thread and act on the thread sensor are minimized by the movement of the thread sensor, which movement is oriented exclusively transversely, preferably at right angles, with respect to the thread. Moreover, the vertical arrangement of the thread sensor makes it possible to use the thread sensor for a very wide range of different thread thicknesses from the thinnest polyester thread to a thick fancy yarn.

Description

Yarn feeding device with new yarn feeler

The invention relates to a yarn feeding device for knitting or knitting machines.

For textile machines, in particular knitting machines or knitting machines, yarn feeding devices are in use, which supply the individual knitting yarns in the required quantity. Various delivery methods are known. It exists:

Positive feeders, in which the yarn delivery loop wrapped by a thread winding determines the yarn delivery quantity,

- Storage specialists in whom the knitting machine by pulling its own thread from a storage drum,

- friction feeders that promote thread slippage, and

- Voltage controlled Fournisseure in which a yarn feed wheel is rotated in response to the thread tension, so that the yarn tension remains as constant as possible. Such feeders are also referred to as negative feeders.

In all these feeders, the task may be to monitor the presence of the thread or to check or measure its tension. Serve usually movable levers that carry at one end an eyelet through which the thread runs or rest with one end to the thread. The movably mounted lever therefore feels whether the thread is taut or whether it sags limply. For this purpose, the lever is movably mounted to be moved transversely to the thread.

For this purpose, GB-PS 1 464 487 discloses a positive guide with axial take-off. The positive thread delivery is achieved by running over the edge of a thread supply drum thread over a fixed hook that determines the expiration point of the thread. Below the Fadenlieferrads a yarn guide loop is arranged in the immediate vicinity of a yarn feeler is arranged. This is formed by a pivotally mounted lever which carries an eyelet end, through which the thread runs. The lever is movable within a transverse to the thread, approximately horizontally oriented plane whose surface normal is oriented parallel to the axis of rotation of the yarn supply drum. A corresponding prior art is formed by DE 23 12 267 and US Pat. No. 3,908,921.

Another basic design of friction or positive suppliers can be found in EP 0 333 482 A1. The Fournisseure described there have a yarn feeler lever which is pivotally mounted about a horizontal axis of rotation. This axis of rotation is oriented transversely to the running thread. The thread feeler lever loads from above obliquely on the thread and is swiveled up and down. It is thus movable within a vertical plane, on which the axis of rotation of the lever is vertical. This plane is substantially parallel to the axis of rotation of the yarn feed wheel.

Due to the inclination of the yarn feeler irregularities in the running yarn, such as nodules, filaments standing out, thickness variations o- the other desired or random yarn effects, lead to a troubled behavior of the yarn feeler lever so that it dances on the current thread. This effect depends on the nature of the yarn.

However, it is increasingly the goal of developments of yarn feeding devices that they work equally well with as many yarn qualities as possible.

On this basis, it is an object of the invention to provide a yarn feeding device with improved yarn feeler.

This object is achieved with the yarn feeding device according to claim 1: The yarn feeding device according to the invention has at least one yarn feed wheel, which is rotatably mounted. The thread feed wheel is associated with a thread guide device, which provides the thread take-off. The thread guide device is set up for oblique withdrawal. Preferably, the yarn feeding device is a positive delivery device. The thread is delivered by rotation of the yarn feed wheel to a yarn consumption point, such as a knitting point.

The yarn feeding device has a yarn feeler extending upwardly away from the yarn. The yarn feeler is movably supported to at least distinguish whether the yarn is taut or limp. For this purpose, it is movably mounted within a transverse to the thread-oriented plane, said plane preferably does not intersect the axis of rotation of the yarn feed wheel. The pivot axis of the yarn feeler is thus preferably oriented approximately parallel to the yarn when it is pivotally mounted. This swings when the thread is flabby, sideways. Otherwise, i. when the thread is taut, it preferably hangs down substantially vertically from its storage. For biasing in the lateral Ausschwenkrichtung preferably a biasing device is used. This may be formed by a suitable force generating means, such as a weight acting on a lever arm, a spring means, magnetic attraction or repulsion forces, or the like.

It is also possible to store the yarn feeler displaceable, wherein it is then oriented substantially vertically, both in a tight and slack yarn.

Due to the essentially rectangular arrangement between see thread sensor and thread is achieved that irregularities of the faster or slower running thread hardly induce significant movements of the yarn feeler. This rests thus relatively quiet and dances little or not.

Due to the upright arrangement of the yarn feeler is achieved that weight forces and acting on the yarn feeler biasing forces on the storage of the yarn feeler not occur as supportive bending moments in appearance. As a result, a robust and at the same time low-friction mounting of the yarn feeler can be achieved with simple means. This allows the application of the yarn feeler even with very thin or fine threads that exert only small forces on the yarn feeler.

The yarn feeler can serve in the form described both as a yarn inlet sensor and as a thread outlet sensor. In both cases, but especially in the latter case, it is expedient to arrange the yarn feeler immediately adjacent to a yarn guiding device. The yarn feeler and the yarn guide device can form an assembly. It is advantageous if this is adjustably mounted with respect to the yarn feed wheel. For an adjustment of the thread flow or the drainage height of the thread is possible. In the case of oblique withdrawal, the outlet angle can be changed to take into account the characteristics of the thread used. The height adjustment is also appropriate for adaptation to other suture drums with greater height. The height adjustment can be used to guide the thread of the yarn feed wheel relatively steep down. By stripping filaments (thread fragments, dust and the like.) The formation of filament rings is counteracted. The displacement direction or adjustment of the assembly is preferably parallel to the axis of rotation of the yarn feed wheel. In an adjustment of the position of this assembly, the position of the thread guide device and the thread feeler remain with respect to each other.

The yarn feeler may be formed as Fadenwäöhter. In this case, it only differentiates between whether a tight thread is present or whether the thread sags or is missing. In this case, a means for distinguishing two positions of the yarn feeler, namely a first position, which it assumes when the thread is taut, and a second position, which it assumes when the thread is limp, is sufficient. The position detecting means may be a switch.

In the other case, the yarn feeler may be formed as a thread tension sensor. For this purpose, it can be connected to a sensor device which detects the magnitude of its deflection. Alternatively, the path to be traveled by the yarn feeler can be reduced to a minimum. In this case, a force measuring device only detects the force exerted by the yarn on the yarn feeler to determine the yarn tension therefrom. Also in this case, it is advantageous that the yarn feeler is substantially perpendicular to the yarn, wherein the direction of action of the force exerted by the yarn on the yarn feeler force is preferably oriented horizontally and transversely to the yarn, wherein the yarn feeler is arranged vertically. Due to the vertical arrangement of the yarn feeler forces in this case, which are caused for example by the weight of the yarn feeler and be changed by Flusablagerung may be ineffective in terms of thread tension detection.

The thread monitor can also be used as a thread store, which can absorb excess thread in the short term. As a result, small excess quantities are temporarily stored and released again when needed without the knitting machine switching off.

Further details of advantageous embodiments of the invention will become apparent from the drawings, the description or claims.

In the drawings, embodiments of the invention are illustrated. Show it:

1 shows a yarn feeding device in the form of a positive supplier in a schematic side view,

FIG. 2 shows a yarn feeler and a yarn guiding device of the yarn feeding device according to FIG. 1 in a schematic perspective view,

3 shows the yarn feeler of Figure 2 in a schematic perspective view,

FIG. 4 shows a modified embodiment of a yarn feeler in an extremely schematized representation,

5 shows a further embodiment of a yarn feeler together with yarn guide device in a schematic perspective view,

FIG. 6 shows a yarn feeding device in an embodiment form as negative feeder with tension-sensing thread feeler,

Figure 7 shows a modified yarn feeding device in the form of a Positivfournisseurs in a schematic side view and

8 shows the yarn feeler and the yarn guide device of the yarn feeding device according to FIG. 7 in a schematic perspective view.

In Figure 1, a yarn feeding device 1 is illustrated, which serves to supply thread 2 to a knitting machine, knitting machine or other textile machine. The yarn feeder 1 has for this purpose a yarn feed wheel 3, which is rotatably mounted on a support 4 and is looped around several times by the yarn 2. The carrier 4 is provided at one end 5 with a mouth-like clamp 6, with which it is to be connected to a suitable holder, such as the machine ring of a knitting machine, as can be seen for example from EP 0 333 482 Al.

At the other end of the carrier 4, a yarn brake 7 is arranged, which keeps the yarn 2 running to the yarn feed wheel 3 at a predetermined tension. The yarn brake is formed for example by two by magnetic force adhering to each other rotatably mounted rings 8, between which the thread 2 passes.

The yarn feed wheel 3 is e.g. attached to a shaft 9, which is rotatably mounted on the carrier 4 and disposed in use substantially vertically. Its axis of rotation 10 is thus oriented approximately vertically. While the yarn feed wheel 3 is disposed below the carrier 4 at the lower end of the shaft 9, at the upper end thereof a drive means, for example in the form of a pulley 11 is arranged. There may be provided not further illustrated pulleys, which also serve to drive the shaft 9.

At least one thread guide device 12, 13 is arranged in front of and / or behind the yarn feed wheel 3, with which the yarn 2 on the yarn feed wheel 3 or from this is conducted. The thread guide device 12 is arranged below the carrier 4 in a position which forces the thread 2 to a skew. In this, the thread 2 runs grazing on the lower edge 14 of the yarn feed wheel 3. The yarn guide device may consist of one or more, in the present case, two eyelets 15, 16, which are formed for example as Keramikösen and arranged in a corresponding holder 17 ^' . The eyelets 15, 16 may be as shown, closed rings or even with discontinuous annular elements, in which the thread is either threaded or inserted through the point of interruption. In the present case, the eyelets 15, 16 are arranged approximately at the same height and at a short distance from each other in order to keep between them a short piece of the running thread 2 calm.

Between the eyelets 15, 16 a yarn feeler 18 is arranged. This is movably mounted. In the present embodiment, it is formed by a lever 19 which is pivotally mounted about a pivot axis 20. Preferably, the bearing is formed on the holder 17 or at least arranged stationary thereto. The pivot axis 20 extends substantially parallel to a line 21 passing through the centers of the eyelets 15, 16. In the present and preferred embodiment, the pivot axis 21 is oriented horizontally, wherein it then intersects the axis of rotation 10. In addition, it cuts, as Figure 3 indicates, an imaginary plane 22 at a right angle, which is oriented transversely to the thread 2.

The lever 19 may be formed as a one or two-armed lever. In the present embodiment, a lever arm carries at its lower free end a thread denöse 23 through which the thread 2 runs. The eyelet 23 lies with the eyelets 15, 16 on the common line 21. The other lever arm (above the pivot axis 20) may be in connection with a spring means 24, for example in the form of a tension spring or compression spring. The spring means 24 is indicated only schematically in FIG. It can also be formed by the elasticity of an end-fixed yarn feeler, by magnet arrangements or the like. Its function consists in the bias of the lever 19 in a predetermined direction of rotation, which is indicated in Figure 3 by an arrow 25. The term "spring means" thus means any device which is suitable for applying a biasing force to the eyelet 23 transversely to the thread running direction. "Spring means" can also be a weight which generates a moment biasing the lever 19.

The yarn feeler 19 is also in communication with a detection device 26. This is in the simplest case adapted to distinguish at least two positions of the yarn feeler 18, namely a first position in which the eyelet 23 is substantially aligned with the eyelets 15, 16, and a second position in which the eyelet 23 from the line 21 is pivoted away. For this purpose, the detection device may consist, for example, of an encoder 27 connected to the lever 19 and a corresponding sensor 28. The transmitter 27 may be formed by a permanent magnet while the sensor 28 is formed by, for example, a magnetically sensitive element such as a thermowell contact switch whose contacts close when the permanent magnet approaches and opens its contacts when the permanent magnet 27 is removed. Hangs the lever 29 vertically and thus aligned with the eyelet 23 and the eyelets 15, 16, the contacts of the Protective tube contact separated while they are closed as soon as the eyelet 23 is swung far enough.

The yarn feeding device 1 described so far operates as follows:

The pulley 11 is driven, for example, by a toothed belt synchronously with other pulleys of other yarn feeding devices sitting together with the yarn feeding device 1 on the machine ring of a circular knitting machine. Accordingly, the yarn 2 is delivered to the knitting machine at the speed given by the yarn feeding wheel 3. This decreases the yarn supplied by the yarn feeder 1 and keeps it so taut. The yarn feeler 18 is biased by the spring means 24 so that the eyelet 23 has a tendency to swing out laterally from the position illustrated in Figure 2. However, the relatively tight thread 2 prevents this, so that the yarn feeler 19 is forced into a substantially vertical orientation.

If the knitting point of the knitting machine does not take sufficient thread or if the thread tears or another disturbance occurs which causes the thread delivered by the thread delivery wheel 3 to become flaccid, the lever 19 pivots about the pivot axis 20. The thread eye 23 then does not align more with the eyelets 15, 16. The transmitter 27 approaches the sensor 28, so that this contact and triggers a corresponding signal. This signal may be an alarm signal, a machine shutdown signal or the like.

Due to the essentially hanging vertical arrangement the lever 19 and, based on the thread 2, exclusively transverse oriented movement of the eye loop 23 are force pulses acting in the direction of yarn travel, not converted into movement pulses of the yarn feeler 19. In other words, because the yarn feeler 18 and the lever 19 move in a plane which is oriented transversely to the yarn 2, wherein the line 21 and the yarn 2 are ideally at right angles to this plane, the yarn feeler 18 be made extremely easy to appeal so that it can be used for very fine threads. However, coarse threads with structure or effect nodes can not cause it to malfunction.

Another essential feature of the yarn feeding device 1 according to Figure 1 is the formation of the yarn guide device 12 and the yarn feeler 18 as a common assembly 29, as illustrated in Figure 2. This assembly 29 is preferably mounted on the support 4 adjustable, as indicated in Figure 1 by an arrow. In a preferred embodiment, the adjustment direction is aligned parallel to the axis of rotation 10. Other adjustment directions are possible. Preferably, the adjustment is a linear adjustment, so that the assembly 19 is height adjustable. This allows the drainage point of the thread to be set. In particular, it can be adjusted how much or to what extent the thread 2 brushes over the edge 14.

Reference is additionally made to FIG. 4 for the spring means indicated only schematically in FIG. Thereafter, the spring means 24 may be arranged or formed so as to apply a torque to the lever 19, which is dependent on the position of the lever 19. For example, it may be desired that the pivoting moment is relatively weak with vertical lever 19, while it increases with increasing deflection. This can be achieved according to Figure 4, characterized in that the angle between a spring element, such as a compression spring 30 and a corresponding lever arm 31 with increasing deflection of the lever 19 from the vertical approaches to a right angle. The compression spring 31 may be, for example, a leaf spring, such as a so-called Ω spring. Also, it may be desired that the pivoting moment has a defined value with vertical lever 19, wherein it decreases with increasing deflection or has a certain course. This can be achieved by the angle between a spring element and a corresponding. Lever arm changes with increasing deflection of the lever in a certain way. For additional explanation, reference is made to DE 199 32 483 A1.

Further modifications are possible. The following examples are to be understood as a non-exhaustive list:

As is indicated in FIG. 5, the yarn feeler 18 can be formed by a vertically movable, for example displaceably mounted element 32, which bears on the yarn 2 between the eyelets 15, 16 from above. This can be done under the effect of its own weight or under the action of a spring means. In the present embodiment, the element 32 is formed by a bracket which rests with a web 33 from above on the thread 2. The web 33 is followed by approximately vertically oriented legs 34, 35, which are connected at its upper end with a slider 36. This is in a vertical guidance, at- For example, slidably mounted in the form of a slot 37. The slider 36 may be made of magnetizable material or contain a magnet, thus serving as a donor. The position thereof is detected by a probe 28, such as a thermowell contact.

The yarn sensor 18 described can be arranged together with a corresponding guide means or even without such equally between the yarn feed wheel 3 and the yarn brake 7.

While the yarn feeler 18 has served in all the above embodiments only to distinguish the tight thread from the floppy thread, it can also be configured as a thread tension sensor, which detects the thread tension in several stages, finely graded or continuously. In this case, it is again possible to fall back on the configuration according to FIG. 2, with the yarn feeler 18 having a lever 19 mounted in a pivotable manner. An example is illustrated in FIG. 6. This example differs from the example described above in that not only the vertical position of the lever 19 is detected by a swung-out position thereof, but additionally the size of the swivel angle is determined. In the simplest case, this is done by instead of the thermowell contact for the sensor 28, a magnetically sensitive element is used, which generates a signal corresponding to the strength of the detected magnetic field. Such an element may be for example a magnetoresistor, a Hall element or the like. Also, optical sensors can find application.

The yarn tension created in this way, the yarn tension Characterizing signal can be processed by the yarn feeding device 1 to other signals. It is also possible to send the signal to a central detection device which evaluates the signal. In addition, it is possible to control with this yarn tension signal, a motor 38, which, as Figure 6 indicates, the yarn feed wheel 3 drives. Also in this case, it is preferable to construct the assembly 29 vertically adjustable. The adjustment can be so large that can be changed from a pure Tangentialabzug in a deep diagonal deduction.

It is also possible to form the yarn feeler 18 away from the path. For this purpose, for example, it is rigidly mounted on a force measuring device, wherein the eyelets 15, 16 define a zigzag path for the thread 2 with the thread running eye 23. Again, the eyelet 23 is at the same height with the eyelets 15, 16, as it was already the case in the above embodiments. The output from the force measuring device force signal then corresponds to the thread tension, which in turn made further evaluations or the motor 38 can be controlled. The control is preferably carried out so that the thread tension on the yarn feeler 18 remains constant.

In Figures 7 and 8, a modified embodiment of a yarn feeding device is illustrative, for which the above description, in particular the description of Figure 1 and 2 based on the same reference numerals applies accordingly. By way of derogation, while the thread guiding device 12 is adjustable in height, the yarn feeler 18 is not height-adjustable, but the lever 19 is provided at its lower end with an oblong, vertically oriented eyelet. the length of which corresponds or exceeds the length of the adjustment path of the thread guiding device 12. The eyelets 16, 16 in front of and behind the yarn feeler 18 are adjusted together in height. The Ösenlängsrichtung is oriented in the direction of the lever 19 and coincides with the adjustment of the guide device 12. As a result, the height of the guide device 12 and thus the withdrawal angle of the thread 2 can be adjusted without changing the conditions for the yarn feeler 18.

In an improved with respect to its yarn feeler yarn feeding device 1, the yarn feeler 18 and an associated yarn guide means 12 preferably form a structural unit which is parallel to the axis of rotation of the yarn feed wheel 3 adjustable. To the yarn feeler 18 includes a lever 19 or other element, which is preferably arranged upright. It thus extends away from the thread in a first transverse direction. In a first embodiment, it is movable in a second transverse direction (pivoting direction) while it is longitudinally displaceably mounted in a second embodiment. By exclusively transverse, preferably oriented at right angles to the thread movement of the yarn feeler caused by the current thread, acting on the yarn feeler motion pulses are minimized. The vertical arrangement of the yarn feeler, it is also possible to process the yarn feeler for a very wide range of different yarn counts from the thinnest polyester yarn to thick effect yarn. List of reference numbers:

1 thread feeding device

2 threads

3 thread feed wheel

4 carriers

5 end

6 clamp

7 thread brake

8 rings

9 wave

10 axis of rotation

11 Pulley

12 thread guide device

13 thread guide device

14 edge

15 eyelet

16 eyelet

17 holders

18 thread sensors

19 lever

20 pivot axis

21 line

22 level

23 thread eyelet

24 spring means

25 arrow

26 detection device

27 donors

28 sensors

29 assembly

30 compression spring lever arm

element

web

leg

pusher

slot

engine

Claims

Claims:

1. Yarn feeding device (1) for knitting machines or knitting machines,

with a carrier (4), which is set up for attachment to a textile machine,

with a yarn delivery wheel (3) rotatably mounted on the support (4) about an axis of rotation (10) and serving to supply the yarn (2),

with a thread guiding device (12) which is arranged in the vicinity of the yarn feed wheel (3) at a position which defines a yarn draw-off,

with a yarn feeler (18) extending upward from the yarn (2),

wherein the yarn feeler (18) is movably mounted within a plane (22) oriented transverse to the yarn (2).

2. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) is oriented substantially vertically with a taut yarn (2).

3. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) in a slack thread (2) is in a laterally swung-out position.

4. Yarn feeding device according to claim 3, characterized in that the yarn feeler (18) is pivotally mounted.

5. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) is oriented substantially vertically in a slack yarn (2).

6. Yarn feeding device according to claim 5, characterized in that the yarn feeler (18) is displaceably mounted.

7. Yarn feeding device according to claim 1, characterized in that at least the thread guiding device (12) is designed to be height adjustable.

8. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) and the yarn guiding device (12) form an assembly (29).

9. Yarn feeding device according to claim 8, characterized in that the assembly (29) with respect to the yarn feed wheel (3) is adjustably mounted.

10. Yarn feeding device according to claim 9, characterized in that the assembly (29) parallel to the axis of rotation

(10) is adjustable.

11. Yarn feeding device according to claim 8, characterized in that the relative position between the thread guide device (12) and the yarn feeler (18) of the adjustment position of the assembly (29) is independent.

12. Yarn feeding device according to claim 1, characterized in that the axis of rotation (10) of the yarn feed wheel (3) is arranged upright in use.

13. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) is arranged in the vicinity of the yarn guide device (12) and serves as a yarn inlet sensor.

14. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) in front of the yarn feed wheel (3) is arranged and serves as a yarn inlet sensor.

15. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) is a thread monitor.

16. Yarn feeding device according to claim 1, characterized in that the yarn feeler (18) is a yarn tension sensor.