The continuous increase in the speed of shuttleless looms has made 10 it practically always necessary to treat weft yarns with oily compounds, in order to reduce yarn tension and allow a more uniform sliding of the yarn to prevent the formation of loops which would lead to yarn breakage

Furthermore, oiling helps at times to correct the irregularities determined by previous yarn treatments. For example, in the case of ace- 15 tate viscose rayon, small acetone residues left on the staple cause the volatilization of the oily substance, applied in the yarn finish, from the outermost layers of the reel and from its ends; this creates great differences in yarn behaviour when inserting the weft yarn from a same reel and it evidently gives rise to serious weaving difficulties in the 20 loom. The application of a thin layer of oil can, in such cases, be a valid remedy.

In the past, the problem had been solved with a paraffining treat¬ ment carried out by causing the yarn, unwound from the reel, to slide over a small block or disk of wax, fixed or even rotating, positioned -5 between the reel and the yarn feeder of the loom.

Even with the advantage of being very simple, said system seldom allowed to obtain a uniform paraffining of the weft yarn. Furthermore, the typical intermittent movement of said yarn, and its variable speed. easily produced grooves and roughness on the surface of the wax block

^0 being used,' which could lead to yarn breakage.

The introduction of liquid paraffin oils has subsequently allowed to overcome these drawbacks, making it also possible to add emulsifying

and/or antistatic agents. Such a treatment has generally been carried out with a device comprising a vessel for the paraffink; liquid, and a roving or band of felt or of textile material, or like, which extracts the oil from the vessel by capillarity and spreads it by direct contact over the

_T outwardly moving yarn. Solutions of this type are described in GB-3981Q1 and in FR-934452. More recently, in said devices, the paraffin oils have been replaced by synthetic oils which give better results.

A further improvement, apt to limit the above drawbacks, has been realized by the Applicant in the EP-B1-340746, which describes a device

10 comprising: an oil container closed by a cover; a roving or a felt band having at least a vertical length, with the lower end plunged into the oil , and a generally horizontal length positioned beneath the cover of the container; and a distributing head, positioned beneath the cover of the container and above the yarn path, consisting of a filtering membrane

15 onto the surface of which rests the roving, and of an element, apt to press the roving onto said membrane, the path of the yarn being such that it laps the membrane from underneath onto its outer surface.

Nevertheless, even this oiler has not been apt to efficiently solve the problem of wear of the oiling surface, which is still very rapid, due

20 to continuous rubbing of the yarn moving at high speeds, and which conse¬ quently requires frequent replacements.

The present invention now offers a valid solution to this problem, by supplying a device to apply liquids, particularly oil, on yarns - to be preferably mounted upstream of yarn feeders for looms - comprising a

25 tank for the oil applied on the weft yarn and an oil distribution unit, characterized in that said oil distribution unit comprises, on one hand, a brush among whose bristles the yarn is guided by suitable guide means and, on the other hand, means to draw close, or move apart, the base supporting the brush and at least part of the means to guide the yarn.

^0 Said yarn guiding means generally comprise a pair of guide eyelets and two guiding rolls joined through an oscillating lever, one of said rolls being fixed in correspondence of the fulcrum of said oscillating

lever and the other roll being lifted and lowered by said lever.

Said means to draw close, or nove apart, the bast- supporting the brush and part of the yarn guiding means, preferably consist of two adjustment screws, one acting on said base and the other one acting on the roll apt to be lifted and lowered by said lever.

Advantageously, the device of the present invention also comprises means apt to remove the weft yarn from the bristles in case of occasional loom stops. Such means may consist of a spring, loaded with a force which is less strong than the yarn tension component acting on the roll apt to be lifted and lowered by the oscillating lever.

The oil level in the tank can be regulated by an overflow.

The device of the present invention will now be described in fur¬ ther detail, with reference to the accompanying drawings, in which:

Fig. 1 is a plan view of the device to apply oil on weft yarns. according to the present invention;

Fig. 2 is a cross-section view of the same device, along the line II-II of fig. 1 ; and

Fig. 3 is a cross-section view of the device, perpendicular to the previous one, along the line III-III of fig. 2. As shown on the drawings, the: device of the present invention com¬ prises a tank 1 for the oil , having at the top a central opening which is closed by a cover 2. The central part of the cover 2 comprises in turn a quadrangular opening 3- from which projects the end of a brush 4 plunged into the oil contained in the tank 1 up to the level L. The brush 4 comprises a support, base 5 and groups of bristles 6. The base 5 of the brush 4 can be lifted or lowered by an adjusting screw 7. operated from the top. which acts on said base.

The oil is introduced into the tank 3 through a hole S. normally closed during operation by a plug Q. On the cover 2 there are provided eyelets 10, 11 - which can also be self-threading eyelets - to guide the weft yarn 12. The guiding of the weft yarn 12 is completed by two rolls 13. 14- of ceramic material, which

are glued onto a lever IS hinged onto a fulcrum 16 in correspondence of the roll 1,3. Under the roll 14 the lever 15 bears onto an adjusting screw

17. which is surrounded by a vertical spring l8 loaded with a force which is less strong than the vertical component of the yarn tension foreseen when the yarn 12 is in a moving condition.

The whole device is supported by an articulated clamp 1Q, inserted onto a bracket 20 which is in turn fixed onto a support 21. typically forming part of the structure of a yarn feeder for looms.

Before starting the loom, the tank 1 is filled with oil through the hole 8, up to the level L, and the plug 9 is then applied thereon. The weft yarn 12 is caused to slide through the first eyelet 10, then over the first roll 13. then between the bristles 6, then over the roll 14. and finally through the second eyelet 11. The oil contained in the tank 1 rises by capillarity through the bristles 6 of the brush 4 and, soaking them, spreads onto the surface of the yarn 12 sliding through said bristles, thereby oiling the; same.

The amount of oil being spread on the weft yarn 12 can be regulated according to its characteristics, and to weaving requirements or to the use being made of the yarn, by acting onto the adjusting screw 17- This latter either lifts or lowers - by way of the lever 15 - the roll 14 in respect of the roll 13, so as to cause the weft yarn 12 to slide in a more or less inclined position, either upwards or downwards, and be: plunged among the bristles 6 to a smaller or greater extent, allowing to vary its oiling degree according to requirements. The constant sliding of the weft yarn 12 through the bristles 6, or over the same, leads to the wear of such bristles. This drawback can be overcome by acting on the adjusting screw 7. which allows to lift the ba¬ se 5 of the brush 4 _? thus leading the yarn 12 to slide in correspondence of bristle parts which are not worn. At this point, to restore the origi- nal configuration of the brush 4- the height, irregularities of the bris¬ tles 6 can be leveled with a blade. When such bristles can no longer be restored, the brush 4 is drawn out through the opening 3 and replaced by

a new one. taking care to position its support base 5 onto the ¹ bottom of the tank 1 by me,ans of the adjusting screw ?•

During use:, there may be^ occasional loom stops; if the weft yarn 12 were to remain in contact with the bristles 6, it would get fully soaked

5 with oil. To avoid this unpleasant drawback, use is made of the spring

18. This latter, being positioned onto the adjusting screw 17- pushes up the roll 14 with a force which is less strong than the> yarn tension component acting on said roll when the yarn is in a moving condition. In this way, during normal running of the loom, the roll 14 is kept in the:

10 lowered position shown in fig. 2, which allows the yarn 12 to be oiled. As soon as the loom stops, yarn tension comes to fail, so that the: force of the spring 18 prevails and lifts the: roll 14, moving the^ yarn 12 out of the bristles 6 of the brush 4- As soon as the loom starts working again, the tension of the yarn 12 is restored, lowering the roll 14 and

15 causing the yarn 12 to slide again among the bristles 6: regular oiling of said yarn thereby starts again.

As can be understood at once from the previous description, the solution according to the present invention proves to be particularly advantageous, as it allows to efficiently apply on the weft yarn - with a 0 very simple and economic system - oil, or any othe:r treatment liquid. hence solving in a very efficient manner the problem of wear of the oil distribution unit. In fact, the possibility to adjust the petition of the base 5 supporting the brush 6, leads to a far more rare replacement of said brush than in the devices of prior art. Furthermore, the possibility 5 to adjust the position of the roll 14 allows to simultaneously weave, with the same device, yarns of highly different characteristics, it being possible to thus proportion the amount of oil spread on the yarn 12.

It is understood that the invention is not limite:d to the special configuration illustrated heretofore, which merely forms a non-limiting

"0 example of its scope, but that any other technically equivalent variants can be introduced therein. In particular, it could be helpful to regulate the: oil level through an inflow pipe and an overflow, allowing oil to be

constantly fed from a pump through said inflow pipe and any oil in excejss to be eliminated through said overflow. Moreover, feir a more uniform feroding, the oil tank 1 ceuild be divided into two compartments connected through a duct , the brush 4 being plunged into one^ of said compartments, while the^ inflow pipe and the: overflow could be provided in the other compartment. Furthermore, the screws 7 and/or 17 could be automatically operated to take into account the wear of the bristles 6 and/or the oil¬ ing requirements, for instance^ in relation to yarn speed and/or to the braking effect meant, to be produced on the yarn in the loom yarn feeder.