EP0889843B1 - Thread feed - Google Patents

Description

The invention relates to a yarn delivery device in the preamble of the claim 1 specified Art.

From EP-A-0 680 917 a yarn delivery device with a stationary storage drum is known with at least one cylindrical, closed peripheral section and with an annular thread control element held stationary, which comprises the peripheral section between a thread storage area and a thread take-off area, wherein the thread control element has a finite band with a flat cross section and wherein an elastic tensioning device is provided which non-positively engages the band with an elastic pretension spans on the peripheral portion.

In a thread delivery device known from GB-C-13 55 518 (FIG. 9) is the thread control element a dimensionally stable one stored outside the storage drum Hollow body that slides over the front end of the storage drum is and with its large diameter cylindrical end portion the cylindrical Surrounding the peripheral portion of the storage drum with a radial distance. The Thread control element has the task of ballooning when pulling of the thread from the thread supply on the storage drum and overhead of the draw-off area in a coaxial to the storage drum arranged at a distance in front of this To minimize the trigger eye. Among other things by the centrifugal force of the order the pulling area of rotating thread has a tendency to bend to remove from the circumference of the storage drum and one in the trigger eyelet to take a helical course. This well-known phenomenon of balloon formation leads to strong mechanical loads on the thread, increasing Tension in the drawn thread and to thread breaks. By suppressing The balloon formation by means of the thread control element becomes these disadvantages eliminated. However, the thread control element is due to its all-round spacing from the peripheral surface of the storage drum unsuitable, even and to ensure certain basic tension in the drawn thread. It is therefore, as mentioned in GB 13 55 518, in addition to the thread control upstream often a so-called bristle brake ring on a housing-fixed Boom attached, the bristles of which touch the drum and the thread brake to ensure the required thread take-up tension. Indeed Such a bristle brake ring has the mechanical disadvantage of one speed-dependent braking effect, i.e. one the thread tension braking effect increasing with increasing speed. This is disadvantageous because the pull-off voltage is approximately over a wide speed range should remain the same in order to achieve optimal entry conditions in the weaving machine.

The object of the invention is to provide a yarn delivery device of the aforementioned type create, in a structurally simple way with the balloon limitation function a largely constant thread take-off tension can be achieved.

The object is achieved according to the invention with the features of the claim 1 solved.

The thread is between the underside of the band and the cylindrical peripheral portion the storage drum is pulled through and runs as it moves additionally in the circumferential direction. The mechanical obstacle of the ribbon suppresses the ballooning tendency of the thread extremely effective. In addition, the contact pressure of the tape on the peripheral portion a uniform and precisely predictable braking effect on the Thread exercised, which surprisingly constant with changes in thread speed remains. In this way, the balloon control by the thread control suppressed and a largely constant thread take-off tension is reached. The elastic pre-tensioning the tape on the peripheral section the thread only overcomes in the passage area under the band that supported on the peripheral portion adjacent to this passage area is. Thanks to the flexibility of the band in the radial direction, the thread forms in the Band, so to speak, a circumferential shaft or a crescent-shaped free space, where the resistance to deformation of the belt essentially independent of speed remains constant. Because of the tension of the tape against the normal force on the thread resulting in the peripheral section regardless of the Speed remains essentially constant, and due to the friction factor of the thread on the belt and on the peripheral section, the advantage results a thread draw tension that remains largely constant. All backgrounds are not reliable for this positive effect of the thread control element to judge. The result of the interaction between the thread, the Band and the peripheral portion, i.e. a largely constant thread take-off tension, is convincing, however. The gap between also unexpectedly affects the constant braking effect at the ends of the belt, obviously because the thread due to the dynamic movement conditions Does not notice circumferential interruption in the tape, provided the thread direction is oblique to the direction of the circumferential gap.

The band is expediently made of flexible metal or plastic with the Specifications according to claim 2. It is conceivable to use a compo-and-tape, the one wear-resistant layer and associated with it another Contains location with other properties.

In the embodiment according to claim 3, the circumferential interruption in Tape as small as possible. The direction of the tape ends is chosen so that the In no case does the thread cross the circumferential interruption in parallel.

In the embodiment according to claim 4, the band is exclusively through positioned the frictional engagement on the peripheral portion. The friction on the peripheral portion is used to stop the tape from moving axially to prevent the thread from pulling.

In the embodiment according to claim 5, the band is a circumferential Shoulder positioned on the storage drum. It can be done this way Tapes of any width and with low tension for sensitive thread material position securely.

In the embodiment according to claim 6, the position of the band is through the bracket fixed, which is conveniently an adjustment of the band in Longitudinal direction of the storage drum and the axial forces that occur records.

A particularly gentle thread entry under the belt is in the embodiment given according to claim 7.

In the embodiment according to claim 8, the tension in the band is only introduced by the spring element, the at least the circumferential gap of the band bridged and pulls the two ends towards each other and in this way one radial contact pressure generated.

In the alternative embodiment according to claim 9, the voltage is and so that the contact pressure of the belt can be changed by the tension adjustment device, to adapt to different deduction conditions or different To be able to make thread material.

In the embodiment according to claim 10, the band becomes contactless, so to speak pressed radially against the peripheral portion by magnetic action.

Alternatively, a closed is used for tensioning the band according to claim 11 Tension ring. This is expediently made of a material that the wave deformation the tape under the action of the thread no noticeable resistance opposed.

In the embodiment according to claim 12, the clamping ring that the Tension band uniformly over the circumferential section, adjust in length, to change the tension.

The embodiment according to claim 13 is particularly advantageous because Foam, elastomer or rubber, or an annular coil spring, Bring constant spring properties, not susceptible to contamination and, above all, this homogeneous material of wave motion of the volume provides negligible resistance The alternative embodiment according to claim 14 generates the voltage of Band by means of an annular membrane made of rubber or an elastomer.

In the alternative embodiment according to claim 15, the voltage applied to the tape by means of a ring body with memory or teeth. This clamping ring can also be used to hold the band in the axial direction be used.

A particularly expedient embodiment emerges from claim 16. The ring hose can already generate a circumferential tension. Each Depending on the degree of filling, the tension or the radial pressure can vary and can be set exactly, without an independent voltage adjustment device.

In the embodiment according to claim 17, the band is solely by friction set, namely under the back pressure of the storage drum.

In the alternative embodiment, the band is at least in regions connected to the clamping ring, which can be favorable for assembly reasons can. In the case of foam, rubber or elastomer, the connection can be made by in-situ Foaming, vulcanizing or sticking and is therefore very uniform, resulting in a completely uniform response of the band is achieved on the passage of the thread.

If the tension ring is as wide as the band, then one becomes achieved uniform support across the width of the belt. Since the tape anyway due to the contact with the storage drum and the shape in the transverse direction is rigid, the tension ring can also be narrower than the band.

In the embodiment according to claim 20, the band is over the tension ring or supported in the holder by means of a support ring comprising this. It no special positioning on the storage drum is required.

In the embodiment according to claim 21, the change in Tension the tape simply by changing the circumferential length of the bracket or the Support ring of the clamping ring is enlarged or reduced, so that the clamping ring can be biased more or less.

Fig. 1

eine schematische Seitenansicht eines Fadenliefergeräts,

Fig. 1A

als untere Hälfte von Fig. 1 ein Detailvariante,

Fig. 2

einen Schnitt einer abgewandelten Ausführungsform,

Fig. 3

eine Draufsicht zu Fig. 2,

Fig. 4

eine Detailvariante,

Fig. 5

ein, beispielsweise bei Fig. 2 und 3 verwendbares Detail in einer Seitenansicht in Richtung der Achse der Speichertrommel gesehen,

Fig.6 A,B;C

eine Variante in einem Schnitt, und in Ansichten in Richtung der Speichertrommelachse,

Fig.7,8

Detailvarianten im Schnitt, ähnlich der Fig. 6A,

Fig.9,10

eine weitere Detailvariante im Schnitt und einer Seitenansicht,

Fig. 11

eine weitere Detailvariante in einem Schnitt, und

Fig. 12

eine weitere Detailvariante in schematischer Darstellung.

Embodiments of the subject matter of the invention are explained with the aid of the drawing. Show it:

Fig. 1

a schematic side view of a yarn delivery device,

Fig. 1A

as the lower half of FIG. 1 a detailed variant,

Fig. 2

2 shows a section of a modified embodiment,

Fig. 3

2 shows a plan view of FIG. 2,

Fig. 4

a detailed variant,

Fig. 5

a detail that can be used, for example, in FIGS. 2 and 3, seen in a side view in the direction of the axis of the storage drum,

Fig. 6 A, B; C

a variant in a section, and in views in the direction of the storage drum axis,

Fig.7.8

Detailed variants in section, similar to Fig. 6A,

Fig. 9,10

another detailed variant in section and a side view,

Fig. 11

another detailed variant in one cut, and

Fig. 12

another detailed variant in a schematic representation.

A thread delivery device F according to FIG. 1, as is typically used to supply a Weaving machine with weft thread is used in a stationary housing 1 shows a drive motor M for a drive shaft shown with its axis 2, with which a winding element 3 is rotatably connected. On the drive shaft 2, a storage drum T is mounted coaxially and non-rotatably. The thread Y runs in the housing 1 in Fig. 1 from the left, is by means of the winding element 3 in successive turns in a thread supply 4 on a peripheral surface 6 of the storage drum T, and depending on the consumption of the weaving machine withdrawn overhead of the storage drum, either directly through an entry device, not shown, and without using a Thread eyelet, or via a thread eyelet 10, which is coaxial with the storage drum T. a boom 9 of the housing 1 is provided. The peripheral surface 6 of the Storage drum has a thread storage area 5 and a draw-off area 7 on. In between is a circumferential, closed, cylindrical circumferential section 8 provided.

The peripheral portion 8 is comprised of a thread control element S, which the Form a circumferentially extending thin band B with a flat Cross section. Band B is not a closed ring, but finally with the ends 16, 17, which lie opposite each other in the area of a gap 18. The Gap 18 can run axially or, as in 18 ', obliquely to the axis of the storage drum T lie. The gap is expediently oriented in such a way that that from the Thread supply 4 drawn thread Y when passing under the band B den Gap 18 passes obliquely and never parallel to the gap 18.

The band B consists of metal, a metal alloy or plastic or is a compound tape, is tensile in the longitudinal direction but flexible, so that it is in Radial direction of the storage drum can be easily deformed. Band B includes the peripheral portion 8 with direct contact and a substantially uniform Contact pressure that is generated by a band B applied Clamping device.

In the simplest form (FIG. 4), the tensioning device is a finite strip 30 made of elastic material, e.g. Foam, rubber or an elastomer that bridges the circumferential gap 18 and adheres to the band B in regions 31, e.g. by gluing, vulcanizing or the like. The tape B should be along its length be homogeneous, which is why there is a positive connection between the Stripe 30 and the tape Bendkbar, but not very useful. The length of the band B is matched to the circumferential length of the circumferential section 8, that the ends in the circumferential gap 18 are as close as possible to one another, without touching or overlapping each other. As soon as the tape B on the Is applied circumferential area 8, the strip 30 or the tensioning device under tension, through which the tape is tensioned and with uniform Contact pressure is pressed onto the peripheral section 8.

In the embodiment of FIG. 1, the clamping device consists of a Circumferential direction closed clamping ring 15, e.g. made of foam, plastic, Rubber or an elastomer that is sized so that it at least the tape presses on the peripheral portion in the radial direction and, if necessary, also generates a tension in the circumferential direction. The clamping ring 14 in Fig. 1 is a foam ring about the same width as the band. The foam ring 15 can be bordered by a closed support ring on which the prestressed foam ring 15 supports.

The band could be with its tensioning device only by friction on the Be circumferential section positioned. In Fig. 1 is another type of positioning chosen because the support ring 20 is supported in an annular holder 13, the is held on a carriage 11 in the boom 9. The carriage 11 can be expediently move by means of a longitudinal adjustment device 12 to hold the band B in an axially optimal position in which the balloon formation of the Y thread largely suppressed and produces a uniform braking effect becomes.

As the lower half of FIG. 1, the clamping ring 14 in FIG. 1A is an annular one Rubber or elastomeric membrane 19, which only rests on the band B. or is at least partially connected to it (e.g. vulcanized) and is held in a comprehensive support ring 20, which in turn is in the holder 13 is supported.

In Fig. 2 another embodiment is indicated in section, in which the Storage drum for thread separation in the thread supply 4 with relative to each other movable, axial rods is formed, the peripheral surface 6 of the storage drum define. In the pull-off direction of the thread behind the thread storage area 5 and in front of the trigger area 7 is the cylindrical peripheral section 8 raised in relation to the peripheral surface 6. On the inlet side of the thread is a circumferential depression, e.g. a conical bevel, formed, over which the band (B) projects freely with a longitudinal edge. This takes place the thread Y has a favorable, only gradually narrowing inlet gap. The clamping ring 14 is, for example, a rubber or elastomer band 23, which Production pressure for tape B generated. In addition, according to FIG. 2 in the withdrawal direction a circumferential shoulder 22 is provided behind the peripheral section 8 to position the tape B.

In order to be able to change the tension applied by the tension ring 14, 3, the tape 23 finally overlapping ends 25 and 24th the end 24 between the fork-shaped end 25 comes in. As indicated by dashed lines at 28, the ends 25, 24 are here together connected to transmit the tension of the tension ring 14 to the band B. The clamping ring 14 is connected to the band in the regions 26 and 27, e.g. through glue dots. Multiple glue dots can be spread over the circumference be provided. It is also conceivable to cover the entire area of the tensioning strap with the strap connect to. In the area 28 in which the ends 24, 25 are connected to one another are, a voltage adjustment device 29 could be arranged to the To be able to vary the tension of the clamping ring 14.

5 is a holder 32 for a voltage adjustment device 29 Tension roller 33 is provided, which is adapted to the curvature of the belt B. Has underside curvature. The end 25 is fixed to the holder 32. The End 24 can be tightened or loosened by turning the tension roller 23 to change the tension of the clamping ring 14 or the contact pressure of the band B to vary. The holder 32 can be in a holder similar to the holder 13 may be arranged on the boom 9.

6A is the clamping ring 14 (FIG. 1), which is a foam ring 15 or the like. is as wide as the band B, the conical inlet slope 21 is indicated by dashed lines. The inner circumference of the foam ring 15 is dimensioned during the shaping that it is conveniently somewhat shorter than the circumferential length of the Circumferential section 8, so that the tape B according to FIG. 6C before application to the Storage drum overlapped with its ends. In this area Foam ring 15 a cavity 34 may be provided. Then the tape B 6B applied to the peripheral portion, then the ends stand opposite and the cavity 34 is enlarged. In this way the Tension is introduced into the band B or the radial pressure force is uniform generated and the tape can work as desired.

An embodiment variant of the voltage adjustment device 29 is indicated in FIG. 6B. The support ring 20 of the foam ring 15 is interrupted with a circumference formed in the area between two spaced flanges an adjusting device attacks to increase the circumferential length of the support ring or reduce and in this way the preload of the foam ring to vary. In a similar form, this voltage adjustment device could be integrated into the holder 13 according to FIG. 1.

In Fig. 7 it is shown that the clamping ring 14, e.g. a rubber or foam ring 15, is narrower than the band B. The support ring 20 is useful to the To be able to store clamping ring 14. In the event that the band B with the clamping ring 14 without external support by friction or by means of the shoulder Fig. 2 is positioned on the peripheral portion 8, the support ring 20 could also be left out.

8 is a possible embodiment of the clamping ring 17 as an annular Rubber membrane 19 indicated, which is also surrounded by a support ring 20 is to be able to support the band with the clamping ring 14 in the holder.

9 and 10 are related to an embodiment in which the clamping ring 14 is an annular body 20 'with teeth or spokes 35 standing inwards, who attack on band B and are connected to it if necessary. The teeth or spokes 35 are elastic and with respect to the radial direction on the axis the storage drum slanted. Connection areas could be provided at 36 his.

In Fig. 11 the tension ring 14 is an annular hose 36 made of elastic material, e.g. Rubber or an elastomer, the interior of which via a valve 37 with a suitable medium, e.g. Air, can be filled to the tension of the tape B. vary. The clamping ring 14 is supported by a support ring 20. The tension ring 14 could possibly be connected to band B at 38. It is possible to arrange the band B only by frictional engagement in the clamping ring 14.

In Fig. 12, the band B, which is made of metal, is formed by an annular magnet arrangement 39 inside the storage drum against the peripheral portion 8 pulled. The magnet arrangement 39 could consist of individual magnets lined up 39 'exist. The band B is here in the circumferential direction of the circumferential section 8 not tensioned, but only uniformly by radial magnetic forces on the Circumferential section 8 pressed.

The tape can be between 5 and 55 mm wide with a thickness of approximately 0.2 mm and optionally a wear-resistant treated or coated inner surface to have. The belt should be flexible enough to be only in certain areas to be deformed radially sickle-shaped by the thread.

Claims (21)

1. A yarn feeder (F) including a housing (1 ) comprising a drive motor (M) for a drive shaft (2), a yarn winding element (3) rotatable with said drive shaft, a stationary storage drum (T) having at least one cylindrical, closed circumferential section (8), and a stationarly held ring-shaped yarn control element (S) surrounding the circumferential section (8) between a yarn store section (5) and a yarn withdrawal section (7), characterized in that said yarn control element (S) is a finite band (B) having a planar cross-section, which band is laid on said cylindrical circumferential section (8) with mutally aligned, neighboring ends, that said band (B) is resistant to extension in the circumferential direction of said storage drum (B) and is made yieldable in the radial direction of said storage drum, and that an elastic tensing device is provided which by force with an elastic preload tenses said band (B) onto said circumferential section (8).
2. The yarn feeder according to claim 1, characterized in that said band (B) consists of a flexible material or a plastic material and has a band width between 5 mm and 55 mm, preferably between 8 mm and 25 mm, at a thickness between 0.1 mm and 2.0 mm, preferably between 0.2 mm and 0.5 mm.
3. The yarn feeder according to claim 1, characterized in that the ends (16, 17) of said band are parallel to each other and perpendicular or inclined relative to the longitudinal direction of said band.
4. The yarn feeder according to claim 1, characterized in that said band (B) is positioned on said circumferential section (8) with the elastic preload of said tensing device and by friction contact.
5. The yarn feeder according to claim 1, characterized in that said band (8) is positioned on said circumferential section (8) by means of a circumferentially continuous shoulder (22) of said storage drum (T).
6. The yarn feeder according to claim 1, characterized in that said band (B) together with its tensing device is supported in a holder (13) and is positioned on said circumferential section (8) by means of said holder (13), and that said holder (13) is adjustable, preferably parallel to the axis of said storage drum (T), and is mounted in a bracket (9) which is fixed to the housing and extends along the circumference (6) of the storage drum.
7. The yarn feeder according to claim 1, characterized in that at the yarn entrance side of said band (B) a circumferentically extending depression (21) is provided in said storage drum circumference (6) or that said cylindrical circumferential section (8) is raised relative to said storage drum circumference (6) adjoining the yarn entrance side.
8. The yarn feeder according to claim 1, characterized in that said tensing device is provided with a spring element (30) which at least bridges the circumferential interruption (18, 18') between the ends (16, 17) and which at least with the band mounted on said circumferential section (8) is tensed in the circumferential direction, said spring element (30) being connected to said band (B) at least locally and preferably consisting of a tensed elastomer or rubber strip or a tension spring.
9. The yarn feeder according to claim 1, characterized in that a tension adjusting device (29) is provided for varying the circumferential tension or/and the contact pressure of the band on the circumferential section (8).
10. The yarn feeder according to claim 1, characterized in that said tensing device for the metallic band (B) is an annular magnet arrangement (39, 39') preferably provided in the storage drum (T).
11. The yarn feeder according to claim 1, characterized in that said tensing device includes at least one closed, elastic tension ring (14) lying on the outer side of said band (B).
12. The yarn feeder according to claim 11, characterized in that said tension ring is made finite with overlapping ends (24, 25) and that both of its ends (24, 25) are adjustably secured in said tension adjusting device (29).
13. The yarn feeder according to claim 11, characterized in that said tension ring (14) is a ring (15) made from plastic foam material, elastomeric material or rubber or consists of a ring-shaped coil spring.
14. The yarn feeder according to claim 13, characterized in that said rubber ring (15) is designed as a circular membrane (19).
15. The yarn feeder according to claim 13, characterized in that said tension ring (14) is a ring body (20') having inwardly protruding resilient spokes or teeth (35), preferably spokes or teeth (35) oriented obliquely preferably in the radial direction to the axis (2) of said storage drum (T).
16. The yarn feeder according to claim 11, characterized in that said tension ring (14) is a ring tube (36) which is inflatable with a medium.
17. The yarn feeder according to claim 11, characterized in that said band (M) is secured in said tension ring (14) by friction contact.
18. The yarn feeder according to claim 11, characterized in that said band (B) is connected over its length to said tension ring (14) at least locally, e.g. by gluing or bonding.
19. The yarn feeder according to claim 11, characterized in that said tension ring (14) at its inner circumference is as broad as said band (B) or smaller.
20. The yarn feeder according to at least one of the preceding claims, characterized in that said tension ring (14), directly or by means of a carrier ring (20), is firmly supported in said holder (13) which is designed in ring form and fixed to the bracket.
21. The yarn feeder according to at least one of the preceding claims, characterized in that said tension adjusting device (29) is provided on the holder (13) or on the carrier ring (20) of said tension ring (14).

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