5 (whether obtained from tuft textile fibres, or from continuous synthetic filaments) and, especially, to an oiler for weft yarns fed to shuttleless looms. Therefore, although hereinafter reference is made above all to the oiling of yarns, it is however understood that the device can be used to apply any other treatment liquids.

10 The continuous increase in the speed of shuttleless looms has made it practically always necessary to treat weft yarns with oily compounds. Oiling helps in fact to correct the irregularities determined by previous yarn treatments. For example, in the case of acetate viscose rayon, small acetone residues left on the filaments cause the volatilization of the

15 oily substance, applied in the yarn finish, from the outermost layers of the reel and from its ends; this creates great differences in yarn beha¬ viour when inserting the weft yarn from a same reel. and it evidently gives rise to serious weaving difficulties in the loom. The application of a thin layer of oil can, in such cases, be a valid remedy. t0 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. Said block or disk was usually positioned between the reel and the loom yarn feeder.

Even with the advantage of being very simple, said system seldom

~5 allowed to obtain a uniform paraffining on 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 being used, which could lead to yarn breakage.

The introduction of liquid paraffin oils has subsequently allowed

30 to overcome the above drawbacks, making it also possible to add emulsify¬ ing and/or antistatic agents. Such a treatment has generally been carried out with a device comprising a vessel for the paraffinic liquid, and a

roving or band of felt or of textile material, or like, which extracts the oil by capillarity from the vessel and spreads it by direct contact over the outwardly moving yarn. Solutions of this type are described in GB-398191 and in FR-934452. More recently, in said devices, the paraffin oils have been replaced by synthetic oils which give better results.

The aforecited devices still involve however different drawbacks. There are in fact difficulties in proportioning the oils and thus, again, problems of unevenness in spreading the oils over the moving weft yarn. Moreover, the roving may hamper the movement of the yarn, causing its breakage, while felt tends to undergo fairly rapid wear.

A further improvement , apt to limit the above drawbacks, has been realized by the Applicant in the EP-B1-340746, which describes a device 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 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. Another device adopting a felt strip is described in the more recent EP-715014-

In such devices, however, some problems still need to be solved: to start with, during yarn passage, the roving or the band of felt or fabric tends to get soiled due to the simultaneous presence of oil and dust, which constantly forms also due to yarn movement. In the long run, this causes the wear and tear of the roving, or band, and it ends up by soil¬ ing also the yarn. Furthermore, the structures adopted in the aforecited patents are still not apt to fully solve the problems of wear tied to continuous rubbing of the yarn. These drawbacks are instead brilliantly overcome by the present invention, which concerns a device to apply liquids, particularly oil, on yarns - to be preferably mounted upstream of yarn feeders for looms -

comprising at least one tank for the liquid and a liquid distribution unit, characterized in that said liquid distribution unit consists of two plates, partially plunged into the liquid of the tank and having substan¬ tially flat cooperating surfaces, drawn close and apt to define a gap, ζ means being provided to guide the yarn and cause it to slide in corres¬ pondence of the end of said gap opposite to that plunged into the liquid. Said yarn guiding means preferably consist of a pair of opposite eyelets, positioned at the two ends of the yarn path inside the device.

Suitably, said cooperating plates extend verticalwise, and their

10 facing surfaces are slightly curved - one being concave and the other one convex - and preferably chromium plated.

Appropriately, moreover, in said device the tank for the liquid is divided into two compartments, connected through a duct, and the liquid level in the two communicating compartments can be regulated through an

15 overflow provided into one of said compartments.

In a first embodiment of the device according to the invention, to proportion the amount of liquid to be applied on the yarn, one of the two cooperating plates is movable by means of a screw, to allow adjusting its distance from the other plate. Whereas, in a second embodiment, to allow

£0 a more exact proportioning of said liquid, the device of the invention comprises a pressure head acting on the yarn, the position of which can be adjusted in order to vary the yarn length sliding in correspondence of the end of the gap - between the two cooperating surfaces of said plates - opposite to that plunged into the liquid.

25 Advantageously, the device according to the invention can moreover comprise means apt to remove the weft yarn from said cooperating plates in case of occasional loom stops. Said means may consist of a dandy roll, loaded with a force which is less strong than that produced thereon by the tension of the yarn, when this latter is drawn from the yarn feeder.

30 The device of the present invention will now be described in more detail, with reference to the accompanying drawings which illustrate, by mere way of example, two preferred embodiments thereof, as well as two

variants of its first embodiment, and in which:

Fig. 1 is a sectional view of a device to apply liquids on yarns, according to a first embodiment of the present invention;

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

Fig. 3 is a plan view, partly sectioned, of the device illustrated in figs. 1 and 2;

Fig. 4 is a detailed section view of the liquid distribution unit of the device, showing a first variant of its embodiment illustrated in figs. 1 to 3;

Fig. 5 is a detailed section view showing a second variant of the liquid distribution unit of the device illustrated in figs. 1 to 3;

Fig. 6 is a lateral section view of a second embodiment of the device according to the present invention; and Fig. 7 is a front section view of the embodiment of the device illustrated in fig. 6.

As already mentioned, the device to apply liquids on yarns, accord¬ ing to the present invention, will be described hereinafter in relation to its use as an oiler of textile yarns to be associated, in particular, to yarn feeders for looms.

Referring first of all to figs. 1 to 5 - illustrating a first embo¬ diment of the device according to the invention - said device comprises an oil tank divided into two compartments 1 and 2, reciprocally connected through a duct 3- The tank compartment 1 is fed with a suitable oil - generally a synthetic oil - from a pump (not shown), through an inflow pipe 4 _> and it comprises an overflow 5- In the tank compartment 2 there are partially plunged two plates 6 and 7, extending verticalwise and positioned parallel and facing each other, so as to define a gap between them, said plates forming the oil distribution unit. In the first variant of this embodiment of the device - shown diagrammatically in fig. 1 , and in detail in fig. 4 - the plate 6 is substantially flat, while the plate 7 is shorter than the plate 6 and is

bent at right angles at its end opposite to that plunged into the oil.

In the second variant of this embodiment of the device - shown in detail in fig. 5 - the two facing and cooperating plates 6 and 7 are of the same length and they each comprise a beveling at their end opposite to that plunged into the oil, external to the tank, said bevelings facing each other and being preferably concave (as shown in fig. 5) •

The plates 6 and 7 are suitably chromium plated (but they could also be made of other suitable material, for example a ceramic material) and their parallel and facing cooperating surfaces are mutually spaced by 0 to 1 mm, and preferably by 0 to 0.5 mm. Advantageously, said coopera¬ ting surfaces of the plates 6 and 7 are slightly curved - as shown in fig. 3 - the surface of the plate 6 being convex and the surface of the plate 7 being concave.

The tank compartments 1 and 2 are provided with a cover 8, whose function is to prevent dust from penetrating into said compartments, so as to reduce to a minimum the forming of dirt and of oil/dust mixtures.

In the variant of fig. 4 ₅ the end of the plate 7 bent at right angles bears onto said cover 8, as shown in fig. 1.

The weft yarn 9 to be oiled is caused to slide along the upper end of the gap defined by the two facing surfaces of the plates 6 and 7; thus, in the case of the variant of fig. 4 , also along the outer edge of the plate 7 bent at right angles, said yarn being guided by a pair of eyelets 10 and 11 (figs. 2 and 3) and by its own tension. To prevent an exceedingly long and extended contact of the weft yarn 9 with the surface of said plates, the plate 7 bent at right angles comprises two peripheral bulges 7A (figs. 2 and 4)•

In the aforedescribed embodiment, the distance between the plates 6 and 7 is adjustable, so as to allow varying the width of the gap defined by said plates. For this purpose, the plate 6 is movable in respect of the plate 7 by means of a screw 12 operated with a handle 13.

As shown in fig. 1 , the whole device is supported by an articulated clamp 14 and is fixed with a bracket J5 upstream of the loom yarn feeder.

Fig. 2 also shows the means allowing to remove the weft yarn Q from the oiling zone in case of loom stops. According to the illustrated embo¬ diment, said means consist of a dandy roll 16, pivoted on a screw 17 and loaded with a force which is slightly weaker than that produced on said roll by the tension of the weft yarn 9-

When the device is working (see fig. l), the oil is fed from the appropriate pump into the tank compartment 1 through the inflow pipe 4- From said compartment, the oil flows through the duct 3 into the tank compartment 2, filling also this latter. Following the principle of communicating vessels, the oil level in the tank compartments 1 and 2 will be exactly the same. On reaching the level L, the excess oil flows back, through the overflow 5 _? into the oil tank from which the pump is fed. In this way, the oil in the two tank compartments 1 and 2 always remains at a constant level. The two plates 6 and 7 are thus plunged for most of their length into the tank compartment 2. By suitably adjusting the distance between said plates - according to the invention, between 0 and 1 mm, and preferably between 0 and 0.5 mm - by means of the handle 13 acting on the screw 12, the oil is caused to rise by capillarity along the gap between the parallel facing surfaces of the plates 6 and 7, up to reaching the top of said gap. This means that, in the first variant (fig. 4). the oil reaches the upper edge of the plate 7 bent at right angles; whereas, in the second variant (fig. 5) , the oil reaches the point of convergency of the two top bevelings of the plates 6 and 1. As already seen, the yarn 9 slides along these particular zones, whereby the liquid from the tank compartment 2, in the specific case oil, is applied thereon as required. The weft yarn 9 is thus oiled in the most efficient manner.

The oil flow on the weft yarn 9 can also be regulated, according to requirements, by reducing or increasing the distance between the parallel facing surfaces of the plates 6 and 7 , through the adjusting screw 12. It is thus possible to easily determine at will the oiling degree for each specific weft yarn 9 _> according to its characteristics, with the evident advantages deriving therefrom.

The two eyelets 10 and 11 - positioned upstream and, respectively, downstream (in respect of the sliding path of the yarn 9) of the oil dis¬ tribution unit, formed by the two plates 6 and 7 - prevent the weft yarn 9 from being deviated from the wanted path, on account of its high speeds and accelerations; this guarantees the continuity of its oiling and eli¬ minates any possibility for the yarn to get caught, thereby considerably reducing the risks of breakage.

Also the use of the dandy roll 16, apt to remove the weft yarn 9 from the plates 6 and 7 in case of occasional loom stops, results to be particularly advantageous. Said dandy roll is pivoted on the screw 17 in such a way that, when being lifted, it follows a circle arc, removing the yarn 9 from the oiling zone; this is particularly helpful to avoid too much soaking of the yarn. In order to be lifted, the dandy roll 16 is loaded with a force which is less strong than that produced thereon by the tension of the yarn 9. In this way, while the loom is working, the tension of the yarn 9 always keeps the dandy roll 16 in a lowered posi¬ tion, allowing the oiling to take place; viceversa, when the loom stops, yarn tension comes to fail and the force loading the dandy roll 16 pre¬ vails and lifts said roll, thereby excluding the oiling operation. As soon as the loom starts working again, yarn tension slowly increases and moves the yarn back into contact with the plates 6 and 7 , so that oiling can again take place.

In its embodiment illustrated in figs. 6 and 7, the device accord¬ ing to the invention comprises - to simplify the structure - a single tank 22 filled with liquid, for example oil, into which are partially plunged two plates 26 and 27, whose surfaces are usually chromium plated or of ceramic material, said plates being separated by a very narrow gap whose width can be adjusted by known means, for instance a suitable ad¬ justing screw (not shown on the drawings). The tank 22 is supported by a bracket 25- hinged onto a support 25A connected to the loom body, and it is closed at the top by a fixed cover 28, which protects the oil from the external dust often accompanying the actual yarn 29 having to be oiled.

The yarn 29 , normally a weft yarn, is guided along the top of the gap between the two plates 26 and 27 by two opposite, self-threading eyelets 30 and 31- As clearly shown in fig. 7, according to this embodiment of the invention the two eyelets 30 and 31 are not aligned, but- they are positioned at considerably different heights.

The whole unit described heretofore is closed at the top by a cover 40 hinged onto the tank 2. According to the invention, said cover carries an inwardly facing pressure head 41, caused to contact the yarn 29 and the position of which can be adjusted by a screw 42, apt to be operated externally to said cover 40.

When the device is working, the tank 22 is filled in any known manner. It can, for example, be divided into two compartments connected through a duct, one of them being fed by a pump, and the level of the liquid (oil) in said tank is regulated by an overflow, as described for the previous embodiment of the device illustrated in figs. 1 to 5• As said, the two plates 26 and 27 are partially plunged into the tank 22. Thanks to the gap formed between them, the oil contained in the tank 22 rises by capillarity, up to reaching the end of said gap along which the yarn 29 is sliding; in this position, the required amount of oil can thus be applied on the yarn 29- As previously mentioned, the two eyelets 30 and 31 , which guide the yarn 29 to slide inside the device, are in a slightly offset position, being at different heights; through said eye¬ lets the yarn is thus led, only to a limited extent, in contact with the zone where the oil is applied thereon. According to the invention, to proportion the amount of oil having to be applied on the yarn - so as to satisfy the requirements of each case, and also prevent the yarn from getting too soaked in oil - one provides, by way of the pressure head 41, to vary the length of the yarn stretch sliding along the zone of oil application, in correspondence of the end of the gap between the two plates 26 and 27- Said head 41 acts on the yarn 29, in the sense of pushing it in the direction of the arrow F. The more the head 41 is pushed forward in the direction F, the longer the

stretch of yarn 29 being in contact with the zone of oil application and, consequently, the greater the amount of oil being applied on said yarn.

To thus proportion the amount of oil applied on the yarn, it is sufficient to adjust the position of the head 41, in the direction of arrow F, by means of the screw 42. By screwdriving the screw 42, from the outside of the cover 40, the pressure head 41 is shifted in the direction of arrow F so as to put a longer stretch of yarn 29 in contact with the oil application zone and thereby increase the amount of oil being applied on said yarn. Viceversa, by unscrewing the screw 42, the pressure head 41 is shifted in the direction opposite to that of arrow F and the yarn 29, thanks to the difference in height between the eyelets 30 and 31 and due to its tension, is lifted from the oil application zone to the extent allowed by the pressure head 41 _> whereby its stretch in contact with said zone becomes shorter and less oil is thus applied thereon. From the previous description, it clearly results how the device of the present invention allows to apply oil - or any other type of treating liquid - on a yarn, in a full and continuous manner, thereby overcoming the drawbacks of the known prior art devices. In particular, the use of chromium plated surfaces or of ceramic surfaces to spread the oil (or other liquid) highly reduces, if not fully eliminates, the problems of wear connected to the use of fabrics and of felts. Moreover, chromium plated surfaces - as opposed to solid paraffin and to fabrics and felts - are far less subject to soiling and can anyhow be perfectly cleaned again, thus preventing the weft yarn from getting soiled and the forming of oil/dust mixtures, which could create friction and break the yarn.

The possibility to adjust the distance between the plates 6 and 7 thanks to the screw 12 and handle 13 - in the embodiment of figs. 1 to 5 - and (with still further advantages) the possibility to proportion the length of the yarn stretch contacting the oil application zone - in the embodiment of figs. 6 and 7 - allow the device of the present invention to be particularly versatile, in that it can be practically adapted to all types of yarns.

The device according to the present invention is moreover extremely simple and economic, and requires far less maintenance than the devices of prior art.

It is understood that the invention is not limited to the special embodiments described heretofore, which merely form non-limiting examples of its scope, but that many variants can be introduced, all within reach of a person skilled in the art, without thereby departing from the scope of the present invention. In particular, the screw 12 (in the embodiment of figs. 1 to 5) or the screw 42 (in the embodiment of figs. 6 and 7), to proportion the amount of oil being applied on the yarn, could be automa¬ tically operated, 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.

Likewise, one could provide for the position of at least one of the eyelets 10, 11, or 30 , 31, to be adjustable, so as to deviate the path of the yarn 9 , or 29, in respect of the plates 6, 7, and 26, 27, and conse¬ quently vary the amount of oil being applied on said yarn.