DESCRIPTION As known, for the discontinuous dyeing of fabrics an apparatus known as a Jigger is widely used.

Normally a jigger has a tank inside of which a dyeing bath is contained in which the fabric is passed, unwinding from an unwinding roller to go to a winding roller.

The fabric is kept at a predetermined distance from the unwinding roller through an expanding equalizer the configuration of which is designed so as to be able to dye even the most delicate fabrics without creases.

In the tank, or outside of it, steam heating means of the bath are arranged.

On top, the apparatus comprises a hood to avoid the dispersion into the atmosphere of the steam that is produced during its use.

Normally, the motion of the rollers is reversible and the fine control of the work tension on the fabric takes place through a load cell.

Current jiggers have numerous drawbacks.

In particular, amongst the most important drawbacks there is the fact that, normally, the temperature T1 of the fabric wound on a cylinder or roller is substantially lower than the temperature T2 of the dyeing bath present in the tank.

Consequently, there is the situation that the greater the temperature difference between T1 temperature of the fabric on the roller and T2 temperature of the dyeing bath, the longer the standing time of the fabric in the dyeing bath.

Another drawback of current jiggers is that there is sometimes substantial difficulty of impregnation of the fabric essentially due to the particular weaving or permeability of the material with which it is made.

Moreover, the drawback of current jiggers is that, normally, the fabric passes inside the dyeing bath and it is not the dyeing bath that is made to pass into the fabric.

As known, this means low penetration of the dyeing bath into the fabric and even if the fabric is sent back inside the bath many times over the situation is not changed due to the constant tension to which the fabric is subjected.

Indeed, in jiggers, the fabric is always stretched so as to prevent creases from forming during the dyeing operation itself.

Due to the constant stretching, therefore, it is not possible to carry out the desired"sponge effect"on the fabric to improve its impregnation.

A further drawback of current jiggers is that the amount of dyeing bath inside the tank is quite small.

For this reason, the fabric-bath ratio is all the more penalized.

Indeed, as known, the greater the amount of dyeing bath, the easier it is to dissolve the ingredients inside it and, consequently, the impregnation of the fabric is made easier.

A solution to this drawback could be that of increasing the amount of bath, but since for technical reasons the rollers with the fabric wound on them must not touch the bath, the size of the tank would have to be substantially increased, with all of the drawbacks that can derive from this situation.

The task proposed of the present finding is that of eliminating the aforementioned drawbacks of the prior art.

In this task an important purpose of the finding is to make an apparatus for the discontinuous open width dyeing of fabrics, which has the temperature of the rollers substantially equal to the temperature of the dyeing bath so as to substantially decrease the standing time of the fabric in it.

Yet another purpose of the finding is to make an apparatus that has a substantial amount of dyeing bath so as to have an improvement of the solution of the ingredients inside it.

The last but not least purpose of the finding is to make an apparatus for dyeing that makes the impregnation of fabric enormously easier and that allows such an operation in extremely short periods of time ensuring, moreover, an optimisation of the penetration of the dye in the fabric, a uniformity of dyeing, easy washing of the fabric, easy preparation of the fabric in the pre-dyeing and post-dyeing step.

In short, this takes place thanks to the fact that water is passed into the fabric and not the fabric into the water like in conventional jiggers.

This task, as well as these and other purposes, are accomplished by an apparatus for the discontinuous open width dyeing of fabrics having a tank inside of which a dyeing bath is contained in which the fabric is made to pass that unwinds from an unwinding roller to go to a winding roller, an expanding equalizer so as to be able to dye even the most delicate fabrics without creases, steam heating means of the dyeing bath, a hood to avoid the dispersion in the atmosphere of the steam that is produced during its use and means for the fine control of the work tension on the fabric, characterised in that at least one of said unwinding or winding rollers comprises first dispensing means of said dyeing bath onto the fabric wound on it.

The present invention also discloses a distribution unit of a dyeing bath for an apparatus for the discontinuous open width dyeing of a fabric, characterised in that it comprises at least one first support tube of said fabric having a plurality of dispensing holes of the dyeing bath uniformly distributed on at least one zone of its side surface, and conveyor means suitable for conveying said dyeing bath to both ends of said first tube so as to distribute it uniformly at said dispensing holes.

Further characteristics and advantages of the invention shall become clearer from the description of a preferred but not exclusive embodiment of the apparatus for the discontinuous open width dyeing of fabrics according to the finding illustrated for indicating and not limiting purposes in the attached drawings, in which : - figure 1 is a sectioned top side view of the dyeing apparatus according to the finding; - figure 2 is a schematic perspective view of the dyeing apparatus according to the finding; - figure 3 shows a variant embodiment of the dyeing apparatus represented in figure 2 according to the finding; - figure 4 is a sectioned view of a roller of the dyeing apparatus according to the finding.

- figure 5 shows a side axial section view of a preferred embodiment of the distribution unit of a dyeing bath for an apparatus per la discontinuous open width dyeing of a fabric of the present finding ; and - figure 6 shows an enlargement of a preferred embodiment of the closure group of the dispensing holes of the present finding.

With reference to the figures described above, the apparatus for the discontinuous open width dyeing of fabrics, hereafter called jigger, wholly indicated with reference numeral 1, comprises a tank 2 inside of which a dyeing bath 3 is contained.

A fabric 4, unwinding from an unwinding roller 5 to go to a winding roller 6, is passed into the dyeing bath 3.

There is also an expanding equalizer 7 suitable for being able to dye the fabric, even if it is a very delicate fabric, without creases.

Moreover, in the tank or outside of it there are steam heating means, not represented, suitable for heating the dyeing bath to the desired temperature.

At the top of the tank a hood 8 is also foreseen, suitable for avoiding the dispersion of the steam into the atmosphere when the jigger is in operation.

Fine control means of the work tension on the fabric are also foreseen, for example a load cell 38.

Advantageously, the apparatus comprises first dispensing means, generically indicated with 10, suitable for dispensing the dyeing bath on the fabric 4 that is wound on the unwinding roller 5.

In a preferred solution the winding roller 6 also comprises second dispensing means 11 of the dyeing bath on the fabric 4 wound on it.

The first and second dispensing means 10 and 11 comprise a plurality of holes, each indicated with 12, which are arranged uniformly on the cylindrical surface of the rollers 5 and 6 to allow the uniform dispensing of the dyeing bath on the fabric wound on them.

Suitably, the first and second dispensing means comprise a closing base 14 arranged at an end of the rollers 5 and 6 and suitable for creating a chamber 20 inside each roller, into which the dyeing bath is sent and from which the dyeing bath, through the holes 12, goes to impregnate the fabric wound on the rollers.

In particular, first and second dispensing means 10 and 11 comprise at least one circulation pump 15, a flow rate measurer 16 and a switch, for example a three-way valve 17 hydraulically connected to the inner surface or to the inner chamber 20 of the rollers 5 and 6.

In a different constructive solution the first and second dispensing means 10 and 11 comprise at least one circulation pump 15 and at least one flow rate measurer 16 for each of the rollers 5 and 6.

In this case, as shall be specified later on, it is not necessary to use the three-way valve since the dispensing of the dyeing bath inside each roller shall be managed by the circulation pump 15 and by each flow rate measurer 16. Inside the rollers 5 and 6, or in just one of the two, a core 21 can be arranged that is able to reduce the width of the inner chamber 20 and therefore reduce the amount of dyeing bath inside each roller.

Suitably, the dyeing bath comes out from the plurality of holes 12 in a substantially radial direction so as to hit the fabric wound on it in an optimal way.

In this way the passage of the dyeing bath through the fabric is obtained, as well as allowing the conventional passage of the fabric into the dyeing bath arranged on the bottom of the tank.

In this way an impregnation of the fabric is obtained that is much superior to the impregnation obtained with the simple passage of the fabric inside the dyeing bath.

The Jigger is provided with two independent variable speed electric motors 30 controlled by vector inverters.

In place of the electric motors it is possible to use hydraulic motors controlled by a fluid-dynamic power unit.

The value of the tension on the fabric is thus accurately controlled by means of the synchronisation of the two motors, obtained through an encoder 39 for a roller and a mathematical model inserted into the PLC.

In such a way the number of turns necessary for each motor to maintain the desired speed and tension is calculated and controlled instantly.

The retroaction between the signal read by the load cell 38 and the inverters also eliminates the residual speed oscillation due to disturbances or the elasticity of the fabric, ensuring perfect control of the tension.

The cylinders for accompanying the fabric 31,32 and 33 are three in number. Two of them are at the bottom of the tank and one is intermediate, arranged outside of the bath 3, on which the load cell is mounted that oversees the fine control of the tension on the fabric during the operation.

The equalizer 7, of the type with a central axis that has already for some time been developed for the most delicate fabrics, has a pair of return rollers with a small diameter 34, preceded by a curved expanding rod 35. The conventional ring with spray nozzles (not represented), supplied with mains water is mounted on each side of the equalizer, to carry out the washing operations, made easier, moreover, by the passage of the dyeing bath through the fabric and not vice-versa like in conventional jiggers.

The distance between the return roller 34 and the roll being wound is kept constant thanks to an encoder connected to the PC/PLC.

The oscillating arm 35 with the return roller is moved according to the comparison made between the reading of the encoder and that of the diameter of the roll.

The Jigger also has a reservoir 40 heated with in direct steam injection and provided with an agitator for perfect mixing of the chemical products.

The load cell 38 takes care of sending the retroaction signal to the motors, to censure the correctness of the tension value on the fabric also during discharge.

The tank is provided with an external level indicator.

The introduction of water into the tank takes place through a litre-counter.

Advantageously, it is possible, through the pump 15, to send the dyeing bath, during the winding of the fabric onto the winding roller, inside the latter.

After the winding of a predetermined amount of fabric on the winding roller 6 the delivery of the bath to it is interrupted sending it to the unwinding roller 5.

In the case of the solution with two pumps, as represented in fig. 2, it is possible to simultaneously send the bath inside the two rollers for a predetermined time period according to requirements.

Now with reference to figures 5 and 6, a distribution unit of a dyeing bath for an apparatus for the discontinuous open width dyeing of a fabric is shown, wholly indicated with reference numeral 110.

The distribution unit 110 comprises a first support tube 210 of the fabric 310 having a plurality of dispensing holes 410 of the dyeing bath uniformly distributed on at least one zone of its side surface, in particular in a central section of the first tube 210.

The dispensing holes 410 are bevelled or even diverge towards the inner side of the first tube 210 so as to promote the canalisation of the dyeing bath through them.

The first tube 210 can be arranged entirely above or below the level of a dyeing bath contained in a dyeing tank (not shown) that carries out the drainage of the dyeing bath released through the dispensing holes 410 towards a recirculation line (not shown) comprising a recirculation pump connected in delivery to an end of the first tube 210.

More specifically, the first tube 210 has the ends closed by bases 121 and 131 in which the support hubs 141 and 151 of the first tube 210 are engaged.

In particular, the support hub 141 has an axial recess 161 and is fitted to the delivery of the recirculation pump so that the dyeing bath, through the axial recess 161, can be introduced into the first tube 201.

The distribution unit 101 also has conveyor means suitable for conveying the dyeing bath to both ends of the first tube 201 so as to distribute it uniformly to the dispensing holes 401.

The conveyor means can be either outside or preferably inside the first tube 201.

In the case illustrated the conveyor means comprise a piping 510 coaxial to and inside the first tube 210 and defining with the first tube 210 a first interspace 600 suitable for reducing the bath volume inside the first tube 210.

The piping 510, at an end thereof, defines a first collector chamber 710 having an inlet 810 for the dyeing bath and a first access route 910 to the first interspace 610, and, at its other end, a second collector chamber 101 having a second access route 111 to the first interspace 610.

The piping 510 also defines a hydraulic connection between the first collector chamber 710 and the second collector chamber 101.

The extreme portions of the side surface of the first tube 210 that face the first collector chamber 710 and the second collector chamber 101 have no dispensing holes 410, so that, as shall be seen, the extreme portions of the first interspace 610 carry out the deflection of the flows entering from a substantially radial direction to a direction substantially parallel to the axis of the first interspace 610.

In the first interspace 610 there are first elements 171 suitable for spacing the first tube 210 and the piping 510.

Of course, the first spacing elements 171 are equipped with through openings 181 suitable for allowing the passage of the dyeing bath along the first interspace 610.

The first spacing elements 171 have, in particular, an annular shape and a section having equally angularly spaced circular holes.

The piping 510 has a second tube 191 having a shorter length than that of the first tube 210 suitable for making the hydraulic connection between the first collector chamber 710 and second collector chamber 101, and a third tube 201 outside the second tube 191 and having a length substantially equal to that of the first tube 210.

The first access route 910 and the second access route 111 to the first interspace 610, respectively, are formed in the portions of the third tube 201 projecting beyond the second tube 191, and, in particular, are formed from an first and, respectively, second plurality of slots angularly spaced around the surface of the third tube 201 and stretching parallel to the axial direction thereof.

The second tube 191 and the third tube 201 define a second interspace 211 at the opposite ends of which there are second spacing elements 221 suitable both for spacing apart the second tube 191 and the third outer tube 201 and for sealing the second interspace 211.

For this reason, the second spacing elements 221, in particular, are formed from rings with a full section.

The piping 510 has an overall wall thickness that is substantially greater than that of the first tube 210.

In particular, the outer tube 210 has a much smaller wall thickness than that of the third tube 201.

This allows the load losses undergone by the dyeing bath in passing through the dispensing holes 410 to be reduced to the minimum with a consequent saving of the head required of the recirculation pump.

Moreover, the piping 510 thus also carries out an important structural function ensuring substantial resistance to flexing and the balancing of the loads to which the entire distribution unit 110 is subjected.

The distribution unit 110 also comprises closure means suitable for selectively closing the dispensing holes 410 so as to adapt the operating width of the zone of the side surface of the first tube acted upon by the dispensing holes 410 to the actual width of the fabric.

The closure means comprise a sleeve 231 that can slide along the outer surface of the first tube 210 and that, in use, can be placed over the dispensing holes 410 to be closed, and sealing means connected to one end of the sleeve 231 and able to be positioned in use beyond an end of the zone of the side surface of the first tube 210 acted upon by the dispensing holes 410 to make a seal between the first tube 210 and the sleeve 231.

The sleeve is also provided with known locking means (not illustrated suitable for locking it in the desired position on the first tube 210.

The sealing means comprise a deformable sealing ring 241 by compression between a counter plate 251 integral with the sleeve 231 and a plate 261 that can be actuated in an adjustable manner to push against the counter plate 251.

The plate 261 and the counter plate 251 have a bolt coupling 271 with nut 281 for adjusting the thrust of the plate 261 on the counter plate 251.

In practice, by actuating the adjustment nut 281, the sealing ring 241 deforms squashing against the portion of the first tube 210 without dispensing holes 410.

In an alternative embodiment (not shown) the sleeve 231 can be fixed to the first tube 210 and have telescopically interconnected stumps that are more or less withdrawn according to the breadth of the fabric.

The distribution unit 110 constitutes the winding and/or unwinding roller of the Jigger apparatus.

The distribution of the bath takes place in the following way.

We shall refer to what happens in a single distribution unit, which represents the unwinding or winding roller arranged above the level of the dyeing bath in the dyeing tank of the Jigger.

Firstly, based upon the actual breadth of the fabric to be dyed, the operating width of the zone of the tube 210 acted upon by the open dispensing holes 210 is adjusted, moving the sleeve 231.

Once the sleeve 231 has been locked into the desired position, the plate 261 is shut against the counter plate 251 so that the sealing 0-ring 241 squashes ensuring the seal between the first tube 210 and the end of the sleeve 231 opposite the zone of the tube 210 acted upon by the dispensing holes 410.

The dyeing bath is supplied by the recirculation pump to the first collector chamber 710 through the inlet 810 of the first collector chamber 710.

The flow entering into the first collector chamber 710 at this point divides into a first flow 301 directed radially through the outlet 910 to the first interspace 610, and a second flow 311 directed axially through the second tube 191 to the second collector chamber 101 and from here radially through the second outlet 111 and again to the first interspace 610.

Preferably, the outflow ports of the first access route 910 to the first interspace 610, of the second access route 111 to the second interspace 610 and of the second tube 191 are identical so that the flow rate of the first flow coming out is equal to that of the second flow coming out.

At the extreme portions of the first interspace 610 the first and second flow coming out strike against the inner surface without holes 410 of the first tube 210 and are therefore deviated by 90° from a radial direction to a direction once again parallel to the axis of the first interspace 610.

In this situation the radial symmetry of the interspace 610 ensures a perfect balancing of the force generated by the impact of the water with the inner wall of the first tube 210.

The first and second flow are therefore conveyed to the opposite ends of the first interspace 231 and, crossing it in opposite directions, meet each other head on.

The dispensing of the dyeing bath through the dispensing holes 410 takes place along a direction that is advantageously in this substantially radial condition.

The distribution system of the dyeing bath of the present finding allows the flow of dyeing bath towards the opposite ends of the first tube 210 to be equally divided so as to carry out homogeneous dyeing.

The equal division of the dyeing bath at the ends of the first tube 210 and the radial symmetry of the conveyor means allow a self-compensation of the forces due to the circulation of the dyeing bath through the distribution unit.

The general operation of the apparatus for the discontinuous open width dyeing of fabrics according to the finding is clear from that which has been described and illustrated.

In particular, during the operation of the Jigger, the dyeing bath is simultaneously sent to the unwinding roller and to the winding roller 5 and 6 so as to impregnate the fabric in an optimal way.

Differently, according to requirements, it is possible to send the dyeing bath just, for example, to the winding roller so as to impregnate the fabric that is winding onto it.

When a predetermined amount of fabric has been wound onto the winding roller it is possible to interrupt the flow of the dyeing bath thereto and to send it to the unwinding roller.

In this way, according to requirements, there is pre- impregnation of the fabric on the unwinding roller before the fabric enters into the dyeing bath present on the bottom of the tank and, after the passage of the fabric in the dyeing bath present in the tank, there is a further impregnation of the fabric whilst it winds onto the winding roller so as to obtain an optimal impregnation of the fabric with the dyeing bath.

In practice, it has been noted how the apparatus according to the finding is particularly advantageous for impregnating the fabric already on the unwinding roller so as to eliminate the temperature differences between it and the dyeing bath.

Moreover, the amount of dyeing bath shall be substantially increased thanks to the fact that it is also present inside the rollers.

The finding thus conceived can undergo numerous modifications and variants all of which are covered by the inventive concept; moreover, all of the details can be replaced by technically equivalent elements.

In practice, the materials used, as well as the sizes, can be whatever according to requirements and the state of the art.