EP1735488A1

EP1735488A1 - Yarn feeder

Info

Publication number: EP1735488A1
Application number: EP05739616A
Authority: EP
Inventors: Gerardo Salton
Original assignee: Iro AB
Current assignee: Iro AB
Priority date: 2004-04-15
Filing date: 2005-04-14
Publication date: 2006-12-27
Also published as: SE0400992D0; CN1942615A; CN1942615B; WO2005100658A1

Abstract

The lower surface (S) of a stopper housing (H) of a yam feeder (F) is continuously flat and essentially parallel to a tangent on the storage region (6) at the location of the stop element (11), and is, at least in a partial region, equipped with an abrasion resistant surface. The yarn feeder comprises a stationary storage body (2) provided at a casing (1), a storage surface on the storage body, the storage surface consisting of storage regions (6) arranged in circumferential direction around a storage body axis (X), a rotatable winding element (3, 4) between the casing (1) and the storage body (2), a stopper housing (H) supported by the casing (1), the stopper housing (H) having the lower surface (S) located adjacent to the storage surface with a yarn passing gap between the lower surface (S) and one storage region (6), a stopping device received in the stopper housing, a stop element (11) of the stopping device being movable through the lower surface (S) and the yarn passing gap towards the storage region, and at least one optoelectronic sensor assembly (20, 22, 24) received in the stopper housing, the sensor assembly including at least one transparent protector (17, 18) located in the lower surface (S) in the neighbourhood of the stop element (11).

Description

YARN FEEDER

The invention relates to a yarn feeder according to the preamble of claim 1.

In prior art yarn feeders of this kind, i.e. so-called measuring feeders for jet weaving machines, the lower surface of the stopper housing is concavely rounded with a similar curvature as the storage surface, or consists of a flat middle region and side regions which are symmetrically inclined in relation to the middle region resulting in a generally concave design of the lower surface. A concave surface shape was deemed to be appropriate in order to allow to position the respective sensor assemblies as close as possible to the storage surface. However, the concave design obstructs a free access from the side, is prone to lint collections between the lower surface and the associated storage region, and results in a relatively broad stopper housing because of the V-arrangement of the sensor assemblies.

It is an object of the invention to provide a yarn feeder of the type as disclosed above, the stopper housing of which is compact in size, can be manufactured for fair costs, and which operates with improved reliability.

This object can be achieved by the features of claim 1.

The combination of the concave storage surface and the flat lower surface of the stopper housing provides free access from both sides to the region where the stop element is situated. The danger of lint collection between the stopper housing and the storage surface and at the location of the stop element is considerably reduced. The flat lower surface is easy to manufacture. The sensor assemblies do not need a V-arrangement resulting in a compact stopper housing design. Moreover, the abrasion resistant surface prevents any wear on the lower surface. Yarn winding contact with the flat lower surface takes place in a very restricted central portion of the lower surface, mainly where the yarn passing gap is the narrowest. This means that the lower surface gains only as little influence on the yam withdrawal procedure as possible resulting in an improved operation reliability of the yarn feeder. The abrasion resistant surface either is formed by an insert, e.g. made from metal or from coated metal, or is provided by a surface coating of the lower surface, respectively. It suffices to provide the abrasion resistant surface in the portion of the lower surface only where yarn contacts might take place. However, for production reasons the entire lower surface may be provided with the abrasion resistant surface.

The transparent protector also ought to be flat and arranged flush in the lower surface, such that no obstacles are created where lint might tend to collect. The sealing of the transparent protector prevents the intrusion of foreign substances into the interior of the stopper housing, e.g. of water or other substances which are applied on the yarn. The sealed and flush arrangement of the transparent protector even allows to use the yarn feeder on water jet weaving machines.

Although a desirable self-cleaning automatically occurs at the flat lower surface, it might additionally be expedient to provide nozzle bodies projecting from the lower surface for additionally and actively cleaning at least the transparent protector from lint and dust. The protruding nozzle body, of course, is situated in a region, e.g. of the lower surface where the yarn windings cannot contact the lower surface.

The stopper housing, expediently, consists of a metallic lower part and a cover lid detachably fixed to the lower part. The abrasion resistant surface may be provided by a plasma coating process on the metallic lower surface.

At the rear the lower surface of the stopper housing is continued by an upwardly inclined further surface which also may contain a transparent protector for a further optoelectronic sensor, e.g. a yarn breakage sensor or wind-on sensor. In order to keep the transparent protector clean a further nozzle body may be provided in this region.

In order to reliably avoid any intrusion of foreign substances into the stopper housing, even the nozzle bodies ought to be sealed in passages of the lower part.

A common pressurised air supply assembly may be installed inside of the lower part for all provided nozzle bodies or cleaning nozzles, respectively. A cleaning action my be provided by permanently or temporarily or pulsatingly blowing out pressurised air. In a preferred embodiment a respective transparent protector is provided on each side of the stopper element. The transparent protectors, expediently, are of substantially rectangular form. Behind the transparent protectors at lest two sensor assemblies, e.g. in view to the possibility of changing the sense of rotation of the winding element, might be provided.

In a preferred embodiment one sensor assembly is a sensor combination consisting of yarn winding store size sensor or reference sensor and a withdrawal sensor, respectively. The sensor combination is contained in a common sensor body structure which is of advantage in view to manufacture, and, furthermore, allows to place the sensor assemblies very close to each other and such that each sensor assembly is allowed to operate at an optimal location. The sensor body structure may expediently consist of plastic injection mould parts which define two pairs of light channels and fixations for diodes (LEDs), phototransistors, lenses, etc. The sensor combination may be prefabricated and pretested and installed as a sub-unit. This structure simplifies replacement of a defect sensor by replacing the entire sensor body structure, while the sealed transparent protector remains in the lower surface of the stopper housing.

In order to achieve optimal sensor operating conditions the mouths of the light channels of the withdrawal sensor are substantially aligned with the position of the stop element, while the mouths of the light channels of the winding store size sensor are placed behind the position of the stop element and closer to the winding element. However, both pairs of mouths are placed such that they scan essentially the same circumferential region of the storage body.

The other sensor assembly, provided at the other side of the stop element expediently is a withdrawal sensor provided for an inversed sense of rotation of the winding element.

In order to achieve a compact size of the stopper housing, both sensor body structures are installed at both sides of a stop element magnet drive in the lower part of the stopper housing. In a preferred embodiment the flat lower side of the stopper housing extends beyond the withdrawal end of the storage body such that the lower surface end portion may function as a yarn control surface (partial balloon breaker).

Embodiments of the invention will be described with the help of the drawing. In the drawing is:

Fig.1 a perspective view of a yarn feeder,

Fig.2 a front view of the yarn feeder of Fig. 1 ,

Fig. 3 a perspective view from below of the stopper housing of the yarn feeder,

Fig. 4 a perspective view from above of a lower part of the stopper housing, and

Fig. 5 a perspective view of a sensor body structure.

A yarn feeder F in Figs 1 and 2, a so-called measuring feeder, is intended for use on jet weaving machines like air jet weaving machines or water jet weaving machines, and comprises a casing 1 which stationarily supports a segmented storage body 2. A rotatable winding element 3 (a winding disk) is provided between the casing 1 and the storage body 2 and has an outlet eyelet 4 through which a not shown yarn exits which then is wound on the storage body 2 in adjacent or separated yarn windings which form a yarn package on the storage body 2. The storage body 2 consists of circumferentially distributed segments 5, each defining a generally concave storage region 6. The segments 5 of the storage body are adjustable in radial direction in order to vary the active diameter of the storage body 2.

A stopper housing H is mounted to a front side of the case 1 such that the stopper housing H is associated to one segment 5. The stopper housing H e.g. is adjustable in radial direction relative to the axis X of the storage body 2 on a guiding surface 8 of the casing 1. In the shown embodiment, the stopper housing H consists of a lower part 10 and an upper cover lid 9. As this is conventional, the stopper housing H contains a stopping device and at least one optoelectronic yarn sensor assembly. As shown in Fig. 2, the stopper housing H has a continuously flat lower surface S which is placed with a small distance (yarn passing gap) to the storage region 6 of an associated segment 5 of the storage body 2. The lower surface S is perpendicular to a radius on the axis X of the storage body 2, or is parallel to a tangent on the storage region 6, e.g. at a location where a stop element 11 is co-operating with the storage region 6. The stop element 11 is driven by a not shown magnetic drive between the shown extended position and a not shown retracted position. In the extended position the stop element 11 even may engage into a recess of the segment 5 to block any withdrawal of yarn from a winding store formed on the storage body 2. In the retracted position of the stop element 11 , the yarn passing gap between the lower surface S and the storage portion 6 is clear for the withdrawal of a predetermined number of windings of the yarn.

As shown in Fig. 3, the lower surface S of the lower part 10 of the stopper housing H is equipped with an abrasion resistant surface C. This surface C either is provided on an insert forming at least a part of the lower surface S, e.g. an insert made from metallic material which may be coated, e.g. by plasma coating, or is provided by a surface coating, e.g. a plasma coating, at least in a partial region of the lower surface S which may be contacted by the yarn windings during the withdrawal process. For easy manufacture, however, the entire free surface of the lower part 10, which preferably is a metallic die cast part, may be plasma coated.

A passage 14 is provided in a central region of the lower surface S. The passage 14 serves to receive the stop element 11 , preferably in sealed condition. A rounded edge portion 13 circumscribes the entire lower surface S. A further, upwardly inclined surface 12 is provided at the rear part of the lower part 10. The further surface 12 may be a little bit concave, as shown.

Substantially rectangular cut-outs 15 and 16 are formed in the lower surface S at both sides of the passage 14 for the stop element 11. The cut-outs 15, 16 extend with their longer dimensions substantially parallel to the direction of the axis X of the storage body 2. Each cut-out 15, 16 receives a transparent protector 17,1 8 behind which a respective sensor assembly 24, 22, 20 is installed in the interior of the stopper housing H. The transparent protectors 17, 18 are flat and are mounted in the cut-outs 15, 16 such that their lower surfaces are flush with the lower surface S. Both transparent protectors are sealed against the intrusion of foreign substances into the interior of the stopper housing H.

Several pairs of mouths 19, 21 , 23 are indicated behind the transparent protectors 17, 18. Each pair of mouths belongs to a respective pair of light channels of the respective sensor assembly 20, 22, 24 (optoelectronic sensor assemblies).

The pair 19 of mouths belongs to the sensor assembly 20 which may be a yarn store size sensor or reference sensor of an optoelectronic type (reflection type sensor). The pair 21 of mouths belongs to the sensor assembly 22 which is a withdrawal sensor (reflection type sensor). The pair 23 of mouths, finally, belongs to the sensor assembly 24 which also is a withdrawal sensor (reflection type sensor). Both sensor assemblies 22, 24 may operate in combination or separately, e.g. when the sense of rotation of the winding element has to be inversed (S or Z-twisted yarn qualities).

In a rear region of the lower surface S, namely where the yarn cannot contact the lower surface S during withdrawal, cut-outs 25 are formed in the lower surface or in the lower part 10, respectively. From the inside of the lower part 10 a respective nozzle body 26 is inserted and sealed in each cut-out 25 such that the nozzle body 26 protrudes over the lower surface S. Each nozzle body 26 receives a cleaning nozzle 31 , the blowing direction of which is oriented (arrow 27) along the lower surface S and across the transparent protector 17 or 18, respectively, in order either permanently or by pulses or temporarily blow pressurised air across the transparent protectors to remove lint and dust.

A further cut-out 28 of substantially rectangular shape is formed in the further surface 12. A transparent protector 29 is sealingly arranged within the cut-out 28 and such that it is essentially flush with the further surface 12. Another optoelectronic sensor assembly 30 is installed inside the stopper housing H behind the transparent protector 29, e.g. a so-called yarn breakage sensor or wind-on sensor (reflection type sensor). At one side of the cut-out 28 a further nozzle body 26 is protruding from the further surface 12, comprising a cleaning nozzle 31 for cleaning the transparent protector 29.

As indicated in Fig. 3, both pairs 23, 21 of mouths of the sensor assemblies 24, 22 are substantially aligned with the location of the stop element 11 , while the pair 19 of the winding store size sensor assembly 20 is placed a little bit further to the rear of the lower surface S, i.e. closer to the further surface 12. In circumferential direction of the storage body 2 the pairs 21 , 19 are a little bit offset in relation to each other, or even may be in line, i.e. placed parallel to the axis X of the storage body 2.

In Fig. 4 the lower part 10 (a die cast form part made of metallic material) contains different fixation means 35 e.g. for the cover lid 9, the not shown magnetic drive for the stop element, and not shown sensor body structures for the respective sensor assemblies. Furthermore, a common pressurised air supply 32 is installed in a cavity 33 for supplying the nozzle bodies 26 with pressurised air. Inbuilt frames 34 serves for mounting the transparent protectors 17, 18 in sealed fashion. The interior cavity 33 of the lower part 10 is substantially rectangular and trough-shaped for later installing the respective components and/or even prefabricated sub-units before the stopper housing H is closed by the cover lid 9.

Fig. 5 shows a sensor body structure B for a sensor combination of the sensor assemblies 22 and 20 which are only generally indicated in Fig. 3, namely for the winding store size sensor and the winding withdrawal sensor, respectively, each having a LED, e.g. for infrared light, and a phototransistor as the receiver of reflection light. The sensor body structure B e.g. consists of injection moulded and assembled plastic parts, namely a base body 36 and a cover lid 37. The sensor body structure B, which even may be equipped with the components in a pre-assembly procedure, is to be mounted in the lower part cavity 33 behind the transparent protector 18.

The sensor assembly 20 in the sensor body structure B includes two light channels 38, 39 which are inclined in relation to each other such that the respective optical light axes intersect below the transparent protector 18 on the storage surface region 6 of the storage body segment 5. In this location a mirror surface may be provided. A light diode 40 and a phototransistor 41 are intended to be inserted in the respective light channels 38, 39 at appropriate fixations. Not shown optical lenses might be provided within the light channels 28, 29 as well.

The other sensor assembly 22 (a withdrawal sensor registering the wound off windings while the stop element 11 is retracted, also is integrated into the base body 36 of the sensor body structure B. The sensor assembly 22 includes two light channels 42, 43 which are inclined in relation to each other such that their optical light axes intersect at the storage surface portion 6 of the storage body segment 5. A light diode 44 and a phototransistor 45 are intended to be inserted into appropriate fixations in the light channels 42, 43. Not shown optical lenses might be provided within the light channels 42, 43. The respective mouths 21 , 19 of the light channels 38, 39, 42, 43 (Fig. 3, not visible in Fig. 5) might be left open in the pre-assembled sensor body structure B, because the transparent protector 18 is fixed in sealed fashion in the lower body 10 already.

The other sensor assembly 24 mounted behind the transparent protector 17 may also be constituted by injection moulded plastic parts forming a sensor body structure (not shown) similar to the sensor body structure B of Fig. 5, however, containing only one pair of light channels for a photodiode and a phototransistor.

Claims

1. Yarn feeder, in particular for jet weaving machines, comprising a stationary storage body (2) provided at a casing (1), a storage surface on the storage body, the storage surface consisting of storage regions (6) arranged in circumferential direction around a storage body axis (X), a rotatable winding element (3, 4) between the casing (1) and the storage body (2), a stopper housing (H) supported by the casing (1), the stopper housing (H) having a lower surface (S) located adjacent to the storage surface with a yarn passing gap between the lower surface (S) and one storage region (6), a stopping device received in the stopper housing, a stop element (11) of the stopping device being movable through the lower surface (S) and the yarn passing gap towards the storage region, and at least one optoelectronic sensor assembly (20, 24, 22) received in the stopper housing, the sensor assembly including at least one transparent protector (17, 18) located in the lower surface (S) in the neighbourhood of the stop element (11), characterised in that the lower surface (S) is continuously flat and substantially parallel to a tangent of the storage region (6) at the location of the stop element (11), and that the lower surface (S) is equipped at least in a partial portion with an abrasion resistant surface (C).

2. Yarn feeder as in claim 1 , characterised in that the abrasion resistant surface (C) is provided on an insert made of abrasion resistant material, preferably metal, the insert defining at least a partial portion of the lower surface, or by an abrasion resistant surface coating on the lower surface (S), respectively.

3. Yarn feeder as in claim 1 , characterised in that the respective transparent protector (17, 18) is flat and is arranged flush with the lower surface, preferably in a sealed condition.

4. Yarn feeder as in claim 1 , characterised in that in a portion of the lower surface (S) extending between the winding element (3, 4) and the stop element (11), preferably in a portion which cannot be contacted by yarn windings, at least one nozzle body (26) protrudes from the lower surface (S), the nozzle body containing at least one cleaning nozzle (31) having a blowing direction (27) oriented alongside the lower surface (S) and across the transparent protector (17, 18).

5. Yarn feeder as in claim 1 , characterised in that the stopper housing (H) comprises a metallic lower part (10) forming the lower surface (S), preferably a metallic die cast part, and a cover lid (9), and that the abrasion resistant surface (C) is constituted by a plasma coating.

6. Yarn feeder as in claim 1 , characterised in that an inclined housing surface (12) continues the lower surface (S) towards the winding element (3, 4), that a further transparent protector (29) of a further optoelectronic sensor assembly (30) is arranged flush and in sealed condition in the surface (12), and that a further protruding nozzle body (26) is provided in the surface (12), the nozzle body having a cleaning nozzle (31) for blowing pressurised air across the further transparent protector (29).

7. Yarn feeder as in at least one of the preceding claims, characterised in that the nozzle body (26) is inserted in sealed condition in a cut-out (25) of the lower part (10).

8. Yarn feeder as in at least one of the preceding claims, characterised in that a pressurised air supply assembly (32) for the cleaning nozzles (31) is installed in an interior cavity (35) of the lower part (10).

9. Yarn feeder as in claim 1 , characterised in that at each side of the stop element (11), seen in circumferential direction of the storage body (2), a transparent protector (18, 17), of a respective sensor assembly (24, 20, 22) is provided, and that the transparent protectors are of substantially rectangular form.

10. Yarn feeder as in claim 9, characterised in by a sensor combination of a winding store size sensor or reference sensor and a withdrawal sensor, that the sensor combination is integrated into a common sensor body structure (B) which is fixed within the lower part (10) behind the transparent protector (18), the sensor body structure (B) containing two pairs of inclined downwardly converging light channels (38, 39; 42,43) and fixations for diodes and/or phototransistors and/or lenses (40, 41 ; 44, 45), the sensor body structure (B), preferably, consisting of assembled plastic injection mould parts (36, 37).

11. Yarn feeder as in claim 10, characterised in that the pair (19) of the mouths of the two light channels is distant in a direction essentially parallel to the axis (X) of the storage body (2) from the pair (21 ) of the mouths of the two other light channels, and that both pairs (19, 21) are offset in circumferential direction of the storage body (2) in relation to each other.

12. Yarn feeder as in claim 9, characterised in that the other sensor assembly (24) is a withdrawal sensor, preferably comprising a sensor body structure consisting of plastic injection mould parts.

13. Yarn feeder as in at least one of the preceding claims, characterised in that both sensor body structures are installed in the lower part (10) at both sides of a stop element magnet drive.

14. Yarn feeder as in claim 1 , characterised in that the lower surface (S) extends beyond the withdrawal end of the storage body (2).