CN1960928A - Apparatus and method for joining textile yarns - Google Patents

Abstract

Device (10) and method for joining textile yarns (16a, 16b). The device (10) comprises a joining chamber (13) in which the ends of two yarns (16a, 16b) to be joined are introduced. The joining chamber (13) can be closed in its closed position and defines a joining space impinged by a fluid. The device (10) comprises, for each yarn (16a, 16b), a first clamping element (21a, 21b) for clamping the end of the yarn (16a, 16b), a second rotating clamping element (14a, 14b) that rotates substantially around the axis of the relevant yarn (16a, 16b) in order to perform untwisting and retwisting of the yarn (16a, 16b), and a shearing element (22). The joining chamber (13), the clamping elements (21a, 21b) clamping the ends of the yarns (16a, 16b) and the detwisting and twisting rotating elements (14a, 14b) are driven by respective and independent drive elements commanded by an electronic control unit (15).

Description

Apparatus and method for joining textile yarns

field of invention

The present invention relates to an apparatus for adding a textile yarn consisting of a group of fibers woven together and its associated method.

In the device according to the invention, the various devices for clamping the end, cutting the tail, stretching, untwisting and re-twisting of the parts that join the yarn, and the elements of the air pressure feeding chamber are made by their respective The different drives are driven individually, which can be controlled and controlled independently by an electronic unit according to preset and presettable parameters and values.

Depending on the characteristics of the yarn, the type of yarn use, the environmental conditions and the signals arriving from appropriate sensors, the electronic unit is adapted to issue command signals to each drive device in order to perform a sequence of various operations for feeding the yarn.

Background of the invention

When incorporating textile yarns, a strict distinction may be made between technical steps, in which operations are performed directly on the fibers that make up the yarn, and auxiliary steps, which are mainly used to position the yarn accurately so that the various operations are correct.

A first type of joining device comprises pneumatic devices which utilize the action of a fluid, usually air, on the fibers which make up the end of the yarn to be joined. Usually, in an initial step, such a device acts on the two strands of yarn so that two ends, so-called tails, of a specific length and shape are obtained with scissors or pliers. Subsequently, both ends of the added yarn are impinged by a blast of compressed air so as to reduce the remaining twist, attempting to parallelize the fibers and reduce the number of fibers affected by the adding operation.

The techniques used to achieve this are various, such as jets inclined relative to the yarn, rotating jets, pulsating jets and others. When the preparatory step is over, the tail is inserted into an accurate joining chamber where a second puff of air penetrates the fibers with mechanical resistance and, due to the geometry of the chamber, tightens the fibers together so that the joining takes place well beautiful. With such equipment, it is extremely difficult to obtain joins with both good mechanical characteristics and good appearance; in fact, these characteristics depend on the geometry of the joining chamber at the air pressure, so it is usually necessary to use a yarn that covers a sufficient A room with a good compromise between the above two requirements.

Primary mechanical equipment is also known, which is used directly on the mechanical manipulation of the fibers constituting the end of the yarn to be joined. With a first mechanical operation on the two ends of the yarn to be joined, ie said detwisting, a central zone is obtained in which the fibers are practically parallel to each other and therefore have no mechanical resistance. Here, the excess is ripped off or cut off so that two tails with the desired length of parallel fibers are obtained. These tails are superimposed, and then a second mechanical operation, or twisting in reverse of the first, is used to reconstruct the structure of the original yarn. With such devices, yarns with optimized aesthetic properties are obtained, but the lack of a penetration step leads to a lack of mechanical resistance and, inter alia, to abrasion.

Another type of equipment is a hybrid pneumatic-mechanical equipment, such as the examples described in DE-A1-3131986 and EP-A-0227370, where the first step of all mechanical operations is to untwist the yarn and obtain The yarn section is then penetrated with a jet of fluid, and finally mechanical operations are performed again in order to detwist the fiber and regenerate the configuration of the yarn. Despite excellent results both in terms of appearance and mechanical resistance, such devices are not widely disseminated due to the enormous mechanical complexity in industrial production. In fact, in order to have the possibility of adapting to different kinds of yarns, it must be possible to vary the amount of mechanical detwisting and/or retwisting as well as the steps and/or duration of the impacts in the pneumatic chamber. Given the shape of the components and the associated drive system, this known device requires at least partial replacement of the components and/or their mechanical readjustment whenever the yarn type and/or quantity is changed, which renders the device wasteful.

The object of the present invention is therefore to obtain a device and a method for adding yarns which allow to obtain the desired technical effect for a wide range of types and quantities of yarns, without increasing the complexity of the device and excluding the above-mentioned known devices defects in.

Applicants have designed and carried out the present invention in order to overcome the disadvantages of the prior art and to achieve other advantages.

Contents of the invention

The invention is described and represented in the independent claims, while the dependent claims describe other innovative features and variants of the invention which differ from the main inventive idea.

The feeding device for preventing yarns according to the invention is of the mixed pneumatic-mechanical type and contains as its main components a pneumatic chamber or feeding chamber, a device for clamping the end of the yarn, a device cooperating with said clamping device. Detwisting and re-twisting devices, stretching and shearing devices.

According to a characteristic characteristic of the present invention, at least from a functional and operational point of view, the components of the above-mentioned equipment are mechanically independent of each other and utilize related and independent triggering means according to the program, operating parameters and signals from the sensors used , in the movement of the whole and each step, it can be triggered separately under the instruction of the electronic control unit.

The independence of operation allows to obtain a substantially universal joining device for yarns without having to modify it mechanically or to apply special parts.

In fact, by arranging the electronic unit, it is possible to modify the triggering parameters of the individual components at each opportunity, adjusting them on the fly specifically to the requirements of the operating cycle, so as to be able to adjust the operation of the device according to the characteristics of the yarn to be added.

In this way we obtain a fully versatile and flexible device, which is cost-effective and capable of operating on virtually any type of yarn without modification and reconfiguration.

Description of drawings

These and other features of the invention will be elucidated in the following preferred embodiments, given as non-limiting examples with reference to the accompanying drawings, in which:

Figure 1 is an overall schematic view of a joining device for textile yarns according to the present invention;

Figure 2 shows an enlarged detail of the device of Figure 1;

Figures 3a, 3b and 3c illustrate the operational steps of the joining cycle performed by the apparatus of Figure 1;

Figures 4a, 4b and 4c show three embodiments of rotary pliers performing untwisting and retwisting of yarn;

Figure 5 shows an enlarged detail of Figure 4b;

Figure 6 is a flow diagram of a method for adding textile yarns according to the invention.

Detailed ways

Referring to the drawings, reference numeral 10 generally designates a feeding device for textile yarns, which are identified by 16a, 16b in Figures 3a, 3b and 3c, according to a preferred embodiment of the present invention.

The device 10 comprises a selectively openable and closable air pressure feeding chamber 13, into which the ends to be fed yarns 16a, 16b are introduced. The air pressure addition chamber 13 is adapted to perform at least some of the following functions in cooperation with the respective clamping device 20 for clamping the ends of the yarns 16a, 16b:

— torsion brakes;

- clamping of the respective yarn 16a or 16b so that during the execution of the untwisting step before the joining and the re-twisting step after the joining is performed, the twist is concentrated in the yarn segment involved;

- Stretch;

- reducing the number of fibers that will form joins;

— tear off the tail;

- Extra large expansion of the excess yarn portion so that two sections of yarn are obtained with the length and number of controlled fibers called tails.

The clamping device 20 is located immediately outside the air pressure charging chamber 13 and comprises first and second pincers arranged on opposite sides of said chamber 13, one (21a) on said charging chamber 13 and the other ( 21b) Under the addition chamber 13. Each pincer 21a, 21b acts on one of the two ends of the yarn 16a, 16b to be added and in particular the associated length of the free yarn.

Each pincer 21a, 21b is mounted on the associated screw 11 whose rotation is performed by the electric motor 12 . With the screw coincident with the first position of the rear end of course indicated by A in Figure 3, the pincers 21a, 21b are open and ready to receive the associated yarn 16a, 16b.

Controlling the appropriate number of rotations of the associated electronic motor 12, the pincers 21a, 21b tighten, clamping the associated yarn 16a, 16b inside them. In this step, (position B in FIG. 3 b ) the pincers 21 a , 21 b perform a stretching operation on the relevant yarn 16 a , 16 b with an amount proportional to the number of rotations transmitted to the relevant motor 12 . The totality of stretching may be the same as that of the two yarns 16a, 16b, or may be different from each other.

Until the screw 11 runs to the position of the second front end of the course (position C in FIG. 3 c ), the motor 12 is triggered again to perform the function of tearing the tail.

The device 10 also comprises a cutting device of scissors 22 for cutting the yarns, which can be used for particularly resistant yarns or yarns with an elastic core, so as to ensure yarn disturbance.

The scissors 22 are activated by a piston supplied with air pressure by means of a controlled electronic valve 23 .

The air pressure adding chamber 13 is a device in which the function of penetrating fibers is performed. Chamber 13 is formed by two separate movable shells, respectively 30 and 31 (Figs. 2, 3a), at least one of which, in this case shell 30, is provided with a series of holes from which the compressed fluid is released on command of the electronic valve 32. Preferably said hole has an axis perpendicular to the axis of said yarn 16a, 16b.

The two shells 30 and 31 move away from/closer to each other, preferably using pneumatic pistons. They can thus assume a first position (position D in FIG. 3 a ) away from each other, in which the feeding chamber 13 is open and the yarn 16 a, 16 b is introduced therein, the ends of which are held by the respective pincers 21 a, 21 b.

Once the yarns 16a, 16b are inside the feeding chamber 13, the two shells 30 and 31 are in contact with each other (position E in FIG. 3b) and the feeding chamber 13 is closed in a sealed manner.

After the two ends of the yarn 16a, 16b have been properly prepared, the addition chamber 13 is closed and then, within a preset time, the control electronic valve is activated so that fluid is introduced into the chamber 13 through the holes 32 and impacts the fibers. The shape of the addition chamber is preferably such that the stream of fluid creates a vortex so that the fibers bond together creating an addition point between the two ends.

Depending on the characteristics of the yarn, the type of yarn use and the environmental conditions, the duration of the gas delivery to the yarn is defined by the electronic control unit 15 . According to the steps of the cycle and the integrality of the tension imparted to the associated yarns 16a, 16b, the pistons that open and close the air pressure that joins the shells 30 and 31 of the chamber 13 and, as we shall see hereinafter, drive the rotation of the scissors 22 The elements of the tongs 14a, 14b and designed to add to the cycle, the electronic control unit 15 is also adapted to the motor 12 driving the tongs 21a, 21b.

In one and/or the other of the housings 30 , 31 , the feeding chamber 13 can be provided with a device for clamping the yarn, which is especially useful for elastic yarns. In this case, on command from the electronic control unit 15, one or more pneumatically controlled pins 33 can be selectively actuated in order to clamp the yarns 16a, 16b in the joining zone, preventing the elastic core of the yarns from excessively shrinking and From joining to leaving.

According to a first variant, the device 10 can be provided with selectively actuated auxiliary components in order to vary the delivery, pressure and temperature of the injected fluid. The auxiliary components are guided by the control unit 15 according to the characteristics of the yarn, the type of yarn use and the environmental conditions.

According to another variant, the device 10 is provided with auxiliary means capable of allowing the injection of a mixture of air and water into the addition chamber 13, the amount of which is controlled by the control unit 15 according to the characteristics of the yarn, the type of use of the yarn and the environmental conditions. Scale revision.

As mentioned above, the apparatus 10 also comprises a first 14a and a second 14b rotating tongs suitable for untwisting and re-twisting the respective yarns 16a, 16b.

The rotary clamps 14a, 14b allow the transfer of a controlled amount of rotation about their respective axes to the associated yarns 16a, 16b. They are located immediately outside the air pressure addition chamber 13, on opposite sides, and each cooperates with an associated yarn clamping jaw 21a, 21b. Each rotary nipper 14a, 14b acts on one of the ends of the yarn 16a, 16b to be added, in particular on a segment of a complete yarn.

Figures 4a, 4b and 4c show three embodiments of rotary tongs 14a, 14b.

In Figure 4a, the rotary tongs 14a, 14b are provided with eyelets 50 for receiving the associated yarns 16a, 16b and are formed on a first gear 40 pulled by a second gear 140 to which the shaft of the electric motor is fixed.

In FIG. 4 b , the rotary pliers 14 a , 14 b also have eyelets 50 for receiving the associated yarns 16 a , 16 b and are mounted on a disk in which the magnet 41 is located, but house the electronic coil 42 on a defined exterior. The controlled rotation of the pliers is controlled by suitably feeding the coil 42 according to the instructions transmitted by the electronic control unit 15 .

In the embodiment shown in FIG. 4 c , the rotary tongs 14 a , 14 b also have eyelets 50 for receiving the relevant yarns and are mounted on a small pneumatic turbine 43 . By triggering a suitable gas jet, clockwise/counterclockwise rotation of the rotary jaws 14a, 14b, eg 44 clockwise rotation and 45 counterclockwise rotation, takes place.

The angular coordinates of each rotary jaw 14a, 14b are controlled by sensors (Fig. 5) providing suitable electronic signals when the clamping pin 47 associated with the moving coil 48 is run to a position allowing entry of the yarn 16a, 16b.

Once the rotary jaws 14a, 14b are clamped in the desired position, the jaws are opened by feeding the coil 48 of the suction pin 47 .

The electronic signal provided by the sensor 46 allows the electronic control unit 15 to measure the amount of rotation performed by the pliers 14a, 14b.

The electronic control unit 15 preferably comprises an electronic card with a microprocessor in which are integrated the functions of processing, piloting the electronic motors, controlling electronic valves and reading out various sensors.

The electronic control unit 15 executes a series of operations on the yarn according to a memory program of a series of parameters linked to the characteristics of the yarn, the addition to be obtained and the environmental conditions. The sequence can be revised based on a signal from a sensor to suit a new working environment.

As shown in the flowchart of Figure 6, we now describe the complete join cycle performed by the aforementioned device 10.

First step - introducing and clamping the yarn: each yarn 16a, 16b is introduced into the device 10 by the respective end clamping jaws 21a, 21b and the corresponding rotating jaws 14a, 14b, and clamped at both ends. tight.

At the end of the operation, four nippers, two stationary nippers 21a, 21b and two rotating nippers 14a, 14b, separate the yarn segments outside the device 10 from those inside the device on which subsequent operations will be performed.

Second step—yarn detwisting: the electronic control unit 15 controls the rotation of the rotary clamps 14a, 14b. The amount and direction of rotation is related to the characteristics of the yarn in order to obtain a removal of twist similar to that of the end clamp jaws 21a, 21b.

Step 3 - Closing the addition chamber: The control unit 15 controls the closure of the pneumatic addition chamber 13 by activating a suitable electronic valve.

Fourth step - stretching the yarn: With the controlled drive of the associated motor 12, the control unit 15 controls the movement of the end clamping jaws 21a, 21b. The totality of the linear movement of the pincers 21a, 21b is related to the yarn characteristics: the larger the totality of drawing, the smaller the number of fibers involved.

Fifth step - clamping the middle part of the yarn: the control unit 15 triggers the electronic valve controlling the outlet of the middle part, so as to prevent the possibly elastic core of the yarn from shrinking too much in the subsequent tearing step.

Step 6—tearing: the control unit 15 controls the end clamping jaws 21a, 21b to move until the cycle ends. The ends of the yarn to be removed are torn by suction.

Seventh step - scissors cut: In order to ensure the release of the two segments of yarn to be removed, the control unit triggers the two scissors 22 .

Eighth step—addition shock: the control unit 15 controls the fluid jet in the addition chamber 13 . The persistent world of the jet depends on the characteristics of the yarn and the set parameters. The direction of impact is such that the fluid not only acts on the fibers of the yarn, causing them to penetrate each other, but also the piston in the central zone is in an inactive position.

Ninth step - Yarn retwisting: the control unit 15 controls the rotating pincers 14a, 14b to rotate in the opposite direction with respect to the direction of the second step: the number of rotations depends on the characteristics of the yarn and the set parameters.

Tenth step - end of cycle: The control unit 15 controls the opening of the shells 30, 31 of the air pressure addition chamber, whereupon the rotary jaws 14a, 14b are released and the rearmost end clamping jaws 21a, 21b return to their positions.

As an auxiliary step, depending on the set parameters, the control unit 15 can trigger the function of the control join.

This step can provide the activation of various control algorithms: every N cycles, randomly distributed tests according to the specific requirements of the operator.

According to another variant, in order to measure the tension of the yarn, a force sensor is provided on at least one of the pincers 21a, 21b at the end of the clamping join. If the function of testing resistance and stretching is activated, the control unit 15 reads the value provided by the force sensor and processes it to determine the added load.

According to another variant, if the function of measuring resistance and stretching is activated, there is a mobile clamp that clamps the other end of the join. In this case, the control unit 15 is thus adapted to control the movement of the movable jaws, which will add tension until it breaks.

In this variant, at the end of the working cycle, the jaws provided with the load chamber and the end clamping jaws are activated and join in this way to remain clamped in both jaws.

The control unit 15 then controls the movement of the movable jaws so that the tension is added and simultaneously records the values provided by the load chamber. When the join is disconnected, the value read from the load cell is effectively zero.

The control unit 15 processes the recorded data and provides the added break and stretch values. If these values do not meet the required levels, the control unit 15 signals that the device 10 is malfunctioning. In order to avoid making joins inconsistent with the required criteria, the operator can set the device 10 so that this condition causes it to stop. Alternatively, if the values obtained when not optimal are deemed sufficient to continue functioning, the circumstances are only signaled at this time, so that maintenance and/or cleaning operations can be programmed.

Claims (19)

1. A device for adding textile yarns (16a, 16b), comprising an adding chamber (13) in which the ends of the two yarns (16a, 16b) to be added can be introduced, said adding chamber (13) Can be closed and defined in its closed position, in order to obtain the joining, the joining room can be impacted by a stream of fluid, for each yarn (16a, 16b) said device comprises: The first clamping device (21a, 21b), the second clamping part device (14a, 14a, 14b) and the shearing device (22), characterized by the feeding chamber (13), the clamping device (21a, 21b) for clamping the ends of the yarns (16a, 16b) and the untwisting and twisting Said rotary clamping devices (14a, 14b) can be driven by respective and independent drive means at the command of the electronic control unit (15), wherein according to the characteristics of the yarn, the type of yarn use and the environmental conditions As at least one of the elements, said electronic control unit (15) is capable of regulating at least the start-up moment, the flow rate and/or the duration of delivery of said fluid on the yarn. 2. The apparatus according to claim 1, wherein said means for clamping the end of the yarn comprises jaws (21a, 21b) controlled by a respective motor (12), characterized in that: for starting from the first position (A ), the second position (B) and the third position (C) move the clamp device (21a, 21b), the electronic control unit (15) can control the driving of the engine (12), wherein in the first position Said pincer means is open and ready to receive the relevant yarn (16a, 16b), in a second position the pincer means (21a, 21b) is closed and clamps the relevant yarn (16a, 16b) inside it, in a third position a tear is obtained Tail function. 3. Apparatus according to claim 2, characterized in that in said second position (B) an adjustable Overall, said pincer means (21a, 21b) are able to perform a stretching operation on the associated yarn (16a, 16b). 4. The device according to any one of the preceding claims, characterized in that the adding chamber (13) is formed by two movable shells (30, 31), at least one of which is provided with a A hole (32) for releasing pressurized fluid. 5. Apparatus according to claim 4, characterized in that said housings (30, 31) can move away/closer to each other, in order to assume a first distant position, wherein said adding chamber (13) is opened and is provided by the respective The ends of the yarns (16a, 16b) accommodated by the pincer means (21a, 21b) can be introduced inside and assume a second mutual contact position, wherein the addition chamber (13) for introducing said fluid passes through said hole ( 32) Close in a tight manner so that the fibers are impacted and joins are obtained. 6. Apparatus according to claim 5, characterized in that said addition chamber (13) is formed such that the fluid is vortexed so that the fibers bind together, creating an addition point between the two ends. 7. Apparatus according to claim 4, characterized in that said addition chamber (13), in one and/or the other of said housings (30, 31), comprises selectively activatable means for The yarns (16a, 16b) are clamped inside the feeding room, especially in the case of elastic yarns. 8. The device according to any one of the preceding claims, characterized in that the electronic control unit (15) is able to regulate the direction and amount of rotation of the rotary tongs (14a, 14b), the rotary tongs (14a, 14b) 14b) Detwisting and re-twisting of the yarn (16a, 16b) can be performed according to the characteristics of the yarn, the type of yarn use and the environmental conditions. 9. Apparatus according to any one of the preceding claims, characterized in that it comprises means actuatable by said electronic control unit (15) in order to selectively alter the flow rate of the fluid injected into said addition chamber (13) , pressure and temperature. 10. Apparatus according to any one of the preceding claims, characterized in that it comprises means actuatable by said electronic control unit (15) in order to, depending on the characteristics of the yarn, the type of yarn use and the environmental conditions, A mixture of gas and water in appropriate proportions is injected into the addition chamber (13). 11. The device according to claim 2, characterized in that the electronic control unit (15) is able to determine the position of the clamping device (21a, 21b) according to the characteristics of the yarn, the type of yarn use and the environmental conditions. Selective triggering in order to regulate the start moment at which stretching of the two segments of the yarn (16a, 16b) is performed. 12. Apparatus according to claim 2, characterized in that the electronic control unit (15) is able to determine the position of the clamping device (21a, 21b) according to the characteristics of the yarn, the type of yarn use and the environmental conditions. Selective triggering in order to control the moment at which the two free ends of the yarn are torn. 13. Device according to any one of the preceding claims, characterized in that, depending on the characteristics of the yarn, the type of yarn use and the environmental conditions, the electronic control unit (15) is able to determine at least the Selective triggering of the shearing device (22) temporarily associated with the clamping device (21a, 21b) and the rotating clamping device (14a, 14b). 14. Apparatus according to claim 1, characterized in that said rotary jaw means (14a, 14b) can be driven by an electric motor (12) commanded by said control unit (15). 15. Apparatus according to claim 1, characterized in that said rotary jaw means (14a, 14b) can be driven by a pneumatic vortex means (43) commanded by said control unit (15). 16. The device according to claim 1, characterized in that said rotary jaw device (14a, 14b) can be controlled by said control unit (15) and an electronic coil device (42) cooperating with a magnet (41) ) driven. 17. The device according to claim 1, characterized in that at least one of the clamping devices (21a, 21b) of the ends of the clamped yarns (16a, 16b) has a Sensor device for resistance and tensile tests. 18. Apparatus according to claim 17, characterized in that said sensor means comprises at least one load cell. 19. Method for feeding textile yarns (16a, 16b) in a feeding device (10) according to any one of the preceding claims, characterized in that it comprises in sequence at least the following steps: the step of introducing the yarns (16a, 16b) into the device (10) and clamping their ends by means of respective pincer means (21a, 21b) and respective rotary pincer means (14a, 14b); the step of untwisting the yarn, wherein the electronic control unit (15) controls the rotation of the rotary clamp device (14a, 14b), the amount and direction of the rotation is related to the characteristics of the yarn; the step of closing said adding chamber (13); With controlled drive of the associated motor (12), wherein said control unit (15) controls the steps of movement of said pincer means (21a, 21b) in order to stretch the yarn ( 16a, 16b), wherein the totality of the linear movement of the pincer means (21a, 21b) is related to the characteristics of the yarn, so that the totality of the stretching transmitted is regulated in a corresponding manner; said control unit (15) controls the movement of the pincer means (21a, 21b) until the end of the process, so that the two ends of the yarn (16a, 16b) to be removed are torn by suction; wherein said control unit (15) triggers the step of the cutting means (22) in order to ensure the release of the two segments of the yarn (16a, 16b) to be removed; wherein said control unit (15) controls the step of adding fluid to the chamber (13), wherein the moment of initiation, flow rate and duration of the jet are functions of the characteristics of the yarn and the parameters set; The step of retwisting the yarn (16a, 16b), wherein the control unit (15) controls the rotating pincers (14a, 14b) to rotate in the opposite direction relative to the direction taken during untwisting, wherein the rotating pincers ( 14a, 14b) the number of rotations is a function of the characteristics of the yarn and the set parameters; a step at the end of the cycle, wherein the control unit (15) controls the opening of the shells (30, 31 ) of the adding chamber (13), The rotating jaws (14a, 14b) are then released and the rearmost end clamping jaws (21a, 21b) return to their positions.

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