"JOINING DEVICE AND JOINING METHOD" ϊjϊ % ϊjϊ ^ H*

FIELD OF THE INVENTION

The present invention concerns a joining device, and a method to join yarns, advantageously textile yarns.

BACKGROUND OF THE INVENTION

Devices are known for joining the terminal parts of textile yarns which, by means of mechanical de-twisting of the terminal parts of the yarns to be joined, provide their co-penetration and reconstitution of the physical continuity of the yarn, and the subsequent mechanical re-twisting.

A device of this type is described and illustrated in WO-A-2005/118449. Applicant has studied and experimented with devices of the type illustrated and described as an example in WO'449 and has perfected both important improvements and a new functioning method suitable to improve the join obtained with said devices.

Applicant has also studied and embodied a new joining chamber suitable to be used in said devices, in order to make it suitable to work with any type of yarn and any type of compatible join.

The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.

SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention or variants to the main inventive idea.

In a known device of the type identified above, for joining textile yarns, there is a joining chamber, able to be closed, inside which the ends of two textile yarns to be joined are introduced; the yarns are first de-twisted for a desired length and for desired values. Inside the joining chamber the textile yarns are hit by pressurized fluid which causes the join.

Said device also comprises, for each of the textile yarns, mechanical gripping and de-twisting means, and means to cut the excess tips.

According to the invention, the gripping means and the de-twisting means may be integrated.

Another variant of the invention provides that the joining chamber has a nozzle to inject compressed air, located in a substantially central position. Another variant provides that the joining chamber has two injection nozzles located at the two sides with respect to the central nozzle and along the axis of the joining chamber.

Another variant provides one or more outlet holes that put the inside of the joining chamber in communication with the outside. A variant provides means, inside the chamber, to temporarily clamp the parallelized fibers.

Another variant provides the chamber having a section conformed as a double facing triangle.

Another variant provides, also according to the type of yarn, a chamber which has a cylindrical, elliptic or rectangular conformation in section.

Another variant provides that the section of the joining chamber remains constant along the whole chamber.

Another variant provides, in order to maximize the joining effect, that along the chamber the section thereof varies in size. Another variant is that the section along the chamber is modified as a geometric figure.

According to the invention, the device is controlled and driven by command and control means, for example of the electronic type, of which the working factors are at least partly pre-settable; the command and control means can govern a plurality of joining devices all working in the same way. It can also govern groups of joining devices operating with at least partly different parameters.

A characteristic of the invention sets the de-twisting as a function of the "S" or "Z" twists present in the textile yarn. A variant of the invention provides to set the number of de-twistings according to the twists per meter present in the textile yarn.

Another variant provides the end stretching factor so as to recoup the lengthening caused by the de-twisting and to thin the ends in order to contain the

size of the knot.

Another variant provides, in addition to the stretching factor, a return factor in order to slacken the de-twisted fibers by a desired value.

Another variant provides to at least temporarily clamp the ends, for example in the case of elasticized yarns or suchlike, to prevent the part to be joined from drooping before the action of the air can at least partly interconnect the fibers.

Another variant provides to regulate the moment the action of the flow of air from the central nozzle starts.

Two other variants, each autonomous, provide to regulate the temporal and/or physical characteristics of the pressurized fluid, such as the duration of the flow of air, flow rate, pressure, the type of flow whether constant or pulsing and, if pulsing, the number of pulsations and the graduality thereof.

Another variant provides to regulate the moment when the ends are cut, in another variant when the means to temporarily clamp the ends is possibly driven and the moment when the means to temporarily clamp the ends is released.

Another variant provides to regulate the moment when the lateral nozzles are activated, delivering the compressed air.

Two other variants, each autonomous, relating to the lateral nozzles, provide to regulate their temporal and/or physical characteristics, such as the duration of the flow of air, flow rate, pressure, the type of flow whether constant or pulsing and, if pulsing, the number of pulsations and the graduality thereof.

Another variant provides to regulate the moment when the twists are again inflicted.

Another variant provides the number of twists that are inflicted. Another variant provides a number of twists inflicted from 2 to 20%, advantageously 10% greater than the original twists.

Another variant provides to inflict a larger number of twists to a single head.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics of the present invention will become apparent from the following description of a preferential form of embodiment, given as a non-restrictive example with reference to the attached drawings wherein: - fig. 1 is a schematic representation of a joining device, the command and control unit and the pressurized fluid unit;

- A -

- fig. 2 is a front view of a semi-shell;

- fig. 3 shows a section from B to B of fig. 2;

- fig. 4 shows, from the section from A to A in fig. 2, the two semi-shells and a reciprocal disposition thereof; - fig. 5 shows a work cycle with the functions able to be introduced in relation to the specific steps of the work cycle. DETAILED DESCRIPTION OF A PREFERENTIAL FORM OF

EMBODIMENT

With reference to the attached drawings, the joining device 10 shown has the joining chamber 19 obtained with the two semi-shells 32-132 facing each other.

The chamber shown in the drawings consists of two semi-shells 33-133 with triangular sections. Depending on the type of yarn 27-127, and the effect to be obtained in the joined yarn 27-127, the section of the chamber 19 can be trapezoid, oval, cylindrical or polygonal. In the drawings the chamber 19 has a constant longitudinal section, but the chamber 19 can vary the sizes of the section, or vary the geometric shape of the section.

Each of the sections, in relation to the position of the jets of pressurized fluid, obtains different and specifically sought joining effects, so that it is possible to maximize the central binding or terminal bindings, or other desired features such as co-penetration or the type of co-penetration.

In cooperation with the semi-shells 32-132 there are mechanical de- twisting/re-twisting means 20-120, gripper means 21-121, also mobile laterally, and scissor means 22-122. There are also positioning means 23-123 which position the semi-shells 32-

132 in an open or closed position so as to create the joining chamber 19.

The semi-shells 32-132 can be facing each other in a specular manner, or positioned vertically staggered as in fig. 4. The staggered position allows to locate better the gripper means 21-121 and the scissor means 22-122. The semi-shells 32-132 have an inlet connector 34-134 in correspondence with the inlet edge of the yarn 27-127 to be joined.

The semi-shells 32-132, if suitable to operate with elasticized yarns or suchlike, have pistons 24-124 that cooperate with a piston-clamping seating 35-

135 present in the opposite semi-shell 32-132.

The pistons 24-124 serve to temporarily clamp the de-twisted fibers.

The semi-shells 32-132, one or both, have a central nozzle 25-125. The central nozzle 25-125 can be orthogonal to the axis of the chamber 19, or tangential to the chamber 19, or again inclined with respect to the axis of the chamber 19.

The semi-shells 32-132, one or both, have two lateral nozzles 26-126 which operate on the terminal parts of the join, the lateral nozzles 26-126 can be in one semi-shell or the other.

The nozzles 26-126 can be orthogonal to the axis of the chamber 19, or tangential to the chamber 19, or again inclined with respect to the axis of the chamber 19.

According to a variant, the pistons 24-124 have the clamping seating 35-135 corresponding to the exit of the lateral nozzles 26-126. Consequently, when the pistons 24-124 are driven, the lateral nozzles 26-126 in any case cannot function. According to a variant, the joining chamber 19 has at least one outlet hole 28 that puts the chamber 19 in communication with the outside.

The sizes of the outlet hole 28 and its position condition the effect to be obtained.

The semi-shells 32-132 have attachment holes 36-136 or similar or comparable elements.

The longitudinal lateral edge of the semi-shells 32-132 has a lead-in edge 36-

136 to facilitate the positioning of the terminal segments of the yarns 27-127 to be joined.

The general functioning of the device 10 is known. The device 10 cooperates with a command and control unit 11 which can govern one or more devices 10.

The command and control unit 11 has a data input and control part 12 and a processing and power part 13.

From the processing and power part 13 the commands 16 exit towards the device 10 and the commands 18 towards the power drive unit 17. The unit 17 uses pressurized fluid. The pressurized fluid is normally pressurized air, but it could be any other fluid or mixture of fluids.

In the diagram in fig. 1, the unit 17 has a single source 31, but there may be

more sources so that, on each occasion or for each channel of use, a specific fluid can be sent, possibly with the addition of substances such as adhesive elements, softeners or other.

In unit 17 there are the lines 37 to 41 which respectively govern: - lines 37 and 39 the lateral nozzles 26-126;

- line 38 the central nozzle 25-125;

- line 40 the positioning means 23-123;

- line 41 the pistons 24-14.

Lines 37-41 all have an opening and closing solenoid 29-429. Lines 37, 38 and 39 all have a pressure regulator 30, 130 and 230, and possibly a flow rate regulator too, able to be controlled by the processing and power unit 13 through the exits 18.

The exits 18 that govern the solenoids 29-229, on command from the unit 1 1, can drive them intermittently. Similarly, the pressure regulators 30, 130 and 230 can vary the value of the pressure and/or flow rate during the individual joining cycle.

Fig. 5 shows the work cycle, clearly and unequically; at the side of every step the factors are listed which the invention provides to vary according to the type of textile yarn and the result to be obtained. Before starting operations to work the textile yarn, according to the type of yarn, the characteristics and the result to be obtained, the invention provides to set the factors of use in the command and control unit 11 through the keyboard

14 and the screen 15. The unit 11 governs all the joining devices 10 that serve that type of yarn. According to a variant, even when there is the same type of textile yarn 27-

127, it is possible to make the joining devices 10 function in groups or individually, with factors of use having at least partly different parameters.

A first type of factor of use is setting the type of twist, "S" or "Z", which characterizes the textile yarn 27-127 to be joined. The setting conditions both the de-twisting step and also the re-twisting step after joining, which is exerted by the de-twisting/re-twisting means 20-120. A second type of factor of use is the definition of the type of textile yarn 27-

127, (animal, vegetable, synthetic, mixed, elastic, semi-elastic, elasticized,

retracted, etc), which characterizes both the stretching action of the segment with parallelized fibers, or with slight inverse twist, and also the subsequent return to slacken the desired value of the fibers.

The stretching and return action is exerted by the grippers 21-121. If the yarn is elastic, or similar, information will be given to the command and control unit which, however, at least during the drive of the central nozzle 25- 125, clamps the ends to prevent the yarn 27-127 from losing its desired position.

The clamping is exerted by the pistons 24-124.

The central nozzle 25-125, but according to a variant also the lateral nozzles 26-126, can work according to different methods in relation to the type of yarn 27-127, its characteristics and, above all, the join effect desired.

For this reason, the jet of pressurized fluid, only in the central nozzle 25-125, or only in the lateral nozzles 26-126, or in all the nozzles, can be regulated in the following factors: - moment when the jet of pressurized fluid begins;

- duration of functioning;

- flow rate or quantity of fluid to be sent;

- pressure at which the pressurized fluid is delivered; said regulation can provide a constant pressure and/or flow rate, or variable pressure and/or flow rate during the cycle;

- possible pulsating deliveries of a desired duration, frequency and number.

It can be defined when the scissor means 22-122 cuts the ends that are not part of the join.

When the ends have been cut, around the moment when the pistons 24-124 release the segments with parallelized fibers or slightly de-twisted, it is defined when the lateral nozzles 26-126 start to function.

It can also be defined, apart from the type of original twist (already inserted), also the number of twists that the means 20-120 must inflict in the joined yarn.

This number of twists can be lower, equal to or more than the number of natural twists of the textile yarn.

It is therefore possible to set, in percentage or numerical terms, a different number of twists.

It is clear, however, that modifications and/or additions of parts may be made

to the joining device 10 as described heretofore, without departing from the field and scope of the present invention.

It is also clear that, although the present invention has been described with reference to specific examples, a person of skill in the art shall certainly be able to achieve many other equivalent forms of joining device and joining method, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby.