CN115701410A

CN115701410A - Device for pneumatic knotless splicing of thread ends or thread ends mounted on textile machines, in particular on automatic winding machines

Info

Publication number: CN115701410A
Application number: CN202210853977.2A
Authority: CN
Inventors: F·拉格诺里; A·贝尔塔齐
Original assignee: Mesdan SpA
Current assignee: Mesdan SpA
Priority date: 2021-08-02
Filing date: 2022-07-13
Publication date: 2023-02-10
Also published as: IT202100020750A1

Abstract

An apparatus for the pneumatic knotless splicing of a yarn end or thread end, the apparatus being mounted on a textile machine, the apparatus comprising: a hollow body supporting the splicing chamber, wherein mounted on the hollow body at a distance from opposite lateral openings of the splicing chamber: a preparation device; locking the clamp; cutting scissors; the pull rod is also provided with a compressed air injection device; a control drum comprising a peripheral set of cam tracks having at least a first cam track and a second cam track for controlling the movement of the movable members of the locking clamps and cutting scissors, wherein the control drum is couplable to a main drive motor mounted on the textile machine; said device is characterized in that it comprises a second drive motor for moving only the tie-rod, which is mounted on the hollow body and is coupled to the angular position sensor and to a transmission member transmitting the motion from the second drive motor to the tie-rod housed in the hollow body, wherein the second drive motor is separate and independent from the main drive motor.

Description

Device for pneumatic knotless splicing of thread ends or thread ends mounted on textile machines, in particular on automatic winding machines

Technical Field

The invention relates to a device for pneumatic knotless splicing of thread ends or stubs to be mounted on a textile machine, in particular on an automatic winding machine.

The invention also relates to a method for pneumatically splicing thread ends or thread ends without twisting, which can be carried out with the device.

Background

The invention is based on a device of this type known from US6199360 and IT1412651 in the name of the same owner.

Common to these known devices is that the movable members of the device are operated by means of a control drum which is rotated by an electrically driven step-reversible main drive motor and which obtains on the casing of said motor a set of cam tracks; each cam track controls the movement of a movable part of the apparatus by means of a corresponding lever, wherein the movable part is: a clamp for locking and a movable part of scissors for cutting the end of the yarn end to be spliced; a spool (spool) of a slide distribution valve that regulates injection of compressed air into the preparation device (preparer device) and the splicing chamber; and a pull rod for withdrawing the end of the cut and prepared yarn end in the direction of introduction into the splicing chamber.

Fig. 9 and 10 show a control drum 40 according to the prior art. It has four cam tracks: a first track P1 for controlling the movable member of one of the two locking clamps and one of the two cutting scissors; a second track P2 for controlling a spool of a slide distribution valve that regulates injection of compressed air into the preparatory apparatus and the splicing chamber; a third track P3 for controlling the movable members of the other of the two locking clamps and the other of the two cutting scissors; and a fourth track P4 for controlling the movement of the

tie rods

41, 42 by means of the control rod 43. The control lever 43 has at one end a cam follower pin 44 following the fourth track P4 and at the opposite end a fork 45 in which a pin 46 fixed at the end of one of the two

tie rods

41, 42 is slidably inserted, the rotation of which is transmitted to the other of the two

tie rods

41, 42 by means of a shaft 47 and

gears

48, 49. On the pin 46 there is a nut 50 for calibrating the rest or zero position of the

tie rods

41, 42.

As shown in fig. 9 and 10, such a fourth track P4 has a cross section developing in a notch or step, as is generally known from US5680751 and US6199360 or IT1412651 in the name of the same owner. The notches or steps define different extreme positions of the tie-

rods

41, 42 and thus the length of the end of the thread end withdrawn in the splicing chamber.

The second trajectory P2 is instead divided into two branches R1, R2, one for operating the spool of the sliding distribution valve in one direction (for injecting compressed air into the preparation device) and the other for operating the spool in the opposite direction (for injecting compressed air into the splicing chamber) when the direction of rotation of the control drum 40 is reversed by returning the

levers

41, 42 to their rest positions.

The presence of the clearance between the fork 45 and the pin 46 allows delaying the bringing back of the

levers

41, 42 to their rest positions when the direction of rotation of the control drum 40 is reversed for operating the spool of the sliding distribution valve in the direction of injecting compressed air into the splicing chamber.

However, in the devices of known type as described above, it is always necessary to reverse the rotary motion of the control drum, which on the one hand lengthens the splicing cycle time and on the other hand does not allow precise control of the angular position of the control drum, which is restored and restored each time the motion is reversed, in particular due to the coupling clearances existing between said control drum and the corresponding main drive motor and between the respective cam track and the corresponding control rod.

Furthermore, in this known type of device, the position of the tie-rod can only be adjusted by means of a "step" according to the notch or step of the respective fourth cam track P4 for controlling the movement of the tie-rod itself. The coupling clearance between the fourth cam track P4, the corresponding control rod 43 with fork 45 and the

tie rods

41, 42 produces a large tolerance in the amount of overlap of the withdrawn yarn ends in the splicing chamber, resulting in unpredictable irregular splices.

It is also not possible to operate the draw-rod to act on the thread end at a different time and/or for a different duration than intended in order to withdraw the end of the thread end in the direction of the splicing chamber at the end of the preparation of the thread end in the preparation device and before the start of the pneumatic splicing.

The adjustment of the rest or zero position of the pull rod is then usually performed manually by the end user, resulting in errors in defining such a rest or zero position. The position of the tie rod cannot be known and precisely controlled during the execution of the splicing cycle. In this respect it is to be noted that incorrect action of the draw-bar on the thread ends to be spliced can lead to splicing joints which do not meet the required standards in terms of appearance and quality.

Finally, as is known, these devices are installed at each processing station of an automatic winder, in particular at each winding station, which cooperates in particular with a respective clearer. In use, it has been found that at the end of each splicing cycle, the spliced yarn tends to vibrate and/or jump when released. The clearer reads this vibration as a defect to be cleared, starting a splicing cycle which is not actually required, thereby extending the winding time. On the other hand, jumps in the spliced yarn can cause it to collide with other parts of the apparatus (e.g. the preparation device), damaging these parts.

Disclosure of Invention

The object of the present invention is to provide a device for pneumatic knotless splicing of yarn ends or stubs to be mounted on a textile machine, in particular on an automatic winder, and a splicing method that can be implemented thereon, which overcome the drawbacks of the prior art.

It is an object of the present invention to provide an apparatus that enables to obtain a splicing joint of high quality and reproducibility.

Another object of the present invention is to provide a device which is flexible to use and easy to adapt to different types of yarn or thread to be spliced, and which can be integrated with the function and operability of the textile machine on which it is installed.

It is a further object of the present invention to provide an apparatus that allows precise control of the angular position of the control drum and the tie rod at any moment during the splicing cycle.

It is a further object of the present invention to provide a device which allows precise and continuous adjustment of the overlapping length of the ends of the thread ends withdrawn in the splicing chamber.

Another object of the present invention is to provide a splicing apparatus and a method that can be implemented with such an apparatus, which enable the release of the spliced yarns to be controlled so as to reduce, if not eliminate, the execution of false splicing cycles and to protect the integrity of the apparatus components.

Another object of the present invention is to create a device which allows to reduce the intervention of manual adjustment, in particular the calibration of the movable parts, and thus to reduce errors and interventions affecting the appearance and quality of the splices.

Another object of the invention is to create an apparatus that makes it possible to reduce the time required to perform each splicing cycle.

Another object of the invention is to create a particularly simple and powerful device, in particular with respect to a control drum, at a limited cost.

These aims are achieved according to the invention by creating a device for pneumatic knotless splicing of thread ends or stubs, as claimed in claim 1, which is mounted on a textile machine, in particular on an automatic winder.

The objects according to the invention are also achieved by a splicing method that can be carried out with the apparatus as claimed in claim 7.

Further features are provided in the dependent claims.

Drawings

The characteristics and advantages of the device for pneumatic knotless splicing of thread ends or stubs to be mounted on textile machines, in particular on automatic winders, and of the splicing method that can be achieved with such a device according to the invention will become apparent from the following illustrative and non-limiting description, with reference to the attached drawings, in which:

fig. 1 is an isometric view of an apparatus for pneumatically splicing thread ends or stubs according to the invention;

FIG. 2 is a schematic front view of a portion of an automatic winding-type textile machine, on each of whose work stations there is mounted an apparatus according to the invention;

fig. 3 and 4 are schematic side views of the device according to the invention mounted on one of the working positions of the textile machine of fig. 2.

Fig. 5 is an isometric view of a detail of the apparatus according to the invention in relation to the drawbar drive unit.

Figures 6 and 7 are perspective views of a control drum of the apparatus according to the invention, provided with control members of the compressed air injection means and of the movable members for the gripper and the scissors, respectively;

FIG. 8 is a side view of the apparatus of FIG. 1 without one of the closed side walls;

FIGS. 9 and 10 are isometric views of a control drum of an apparatus according to the prior art, with one of the cam tracks being used to operate the tie rod;

figure 11 shows a plan development (in solid line and in section pattern) of the overlapping cam tracks of the control drum of the device according to the invention, compared with the cam tracks (in broken line) of the control drum according to the prior art in figures 9 and 10;

fig. 12 to 21 schematically show a top view of a sequence of steps of a splicing method according to the invention, which can be implemented with an apparatus according to the invention.

Detailed Description

With reference to the figures, a device 1 for the pneumatic knotless splicing of yarn ends or stubs is shown to be mounted on a textile machine, in particular on an automatic winder 100 provided with an electronic control unit 200.

It is noted that in the present disclosure, reference will be made only to the apparatus 1 with ambient compressed air; however, it is clear to the person skilled in the art that the apparatus 1 can also have compressed air with water added or heated compressed air.

With reference first to fig. 2, it shows schematically a part of a textile machine consisting of an automatic winder 100 with a plurality of processing or winding stations 101 and an electronic control unit 200 from which the control of the operating machine can be set and given.

Each winding station 101 comprises: a spool 102 from which the yarn or thread to be wound into a package is unwound; a detection device or clearer 104 for checking the continuity and condition of the yarn being unwound from the spool 102 and wound onto the winding cradle or tube 103 to form a package; and a rotating drum 105 on which the log being formed rests on the rotating drum 105.

The device 1 according to the invention is installed on each winding station 101 to perform the splicing of two ends of yarn on the package side CR and on the spool side CS respectively, in the event of interruption of the yarn being wound due to accidental breakage or elimination of the defective portion indicated by the clearer 104, or in the event of replacement due to exhaustion of the spool 102.

Near the spool 102 there is a head support bar 106, which is operated by a respective motor 107 and cooperates with the device 1 for introducing the thread end on the spool side CS inside the device 1.

On each winding station 101 there are

rotatable arms

108, 109, each provided with a respective suction inlet for catching the thread ends on the package side and the bobbin side and introducing them into the apparatus 1.

The textile machine will not be described further, since it is of known type and is not tied to the object of the present invention.

The clearer 104, the

rotatable arms

108, 109, the head support bar 106 and the associated motor 107 and the rotary drum 105 are controlled by an electronic control unit 200, which also controls each device 1.

The apparatus 1 comprises a hollow body 2 closed on opposite sides by side walls 3, on the top of which a splicing chamber 5 (splicing, i.e. connecting or braiding) is mounted, provided with two opposite lateral openings between which a longitudinal slot extends, open on the top, for introducing therein the two ends of yarn CR, CS to be spliced.

A cover 6 or chamber cover is movably mounted on the hollow body 2 and is adapted to close temporarily at the top the longitudinal slot of the splicing chamber 5 after the introduction inside it of the two ends of yarn CR, CS to be spliced.

In the splicing chamber 5, one or more nozzles (not shown) open for injecting jets of compressed air therein for splicing the two ends of yarn CR, CS, as known.

At least the following components are arranged in order on each side of the splicing chamber 5, spaced apart from one another:

-preparation means 7,8 for pneumatically preparing the ends of the thread CR, CS to be spliced,

a

draw bar

9, 10, which draw

bar

9, 10 draws the end of the thread ends CR, CS to be spliced from the

preparation device

7,8 towards the interior of the splicing chamber 5,

locking clamps 11, 12 for locking the ends of the yarns CR, CS introduced into the splicing chamber 5, wherein each locking clamp acts on the external portion of the respective end of yarn entering the splicing chamber 5, and wherein each locking

clamp

11, 12 has a fixed member and a movable member;

cutting

scissors

13, 14 for cutting the end of the thread ends introduced into the splicing chamber 5 at the portion of the thread ends CR, CS exiting the splicing chamber 5; each

scissors

13, 14 has a fixed member and a movable member;

yarn guide plates

15, 16 for guiding the yarn ends CR, CS.

The

preparation device

7,8 consists of a tubular element into which one or more nozzles for injecting jets of compressed air open; the thread ends CR, CS are introduced into the

preparation devices

7,8 by suction accompanied by a depression near the inlet of said devices, generated by the jets of compressed air injected therein. The compressed air injected into the

preparation devices

7,8 prepares the cut end of the thread end by untwisting and/or opening the thread end.

There are also compressed air injection means for injecting compressed air in the

preparation devices

7,8 and the splicing chamber 5.

In the embodiment shown, such a compressed air injection device comprises a single distribution valve 17, which is of the sliding type known per se and can be supplied by means of a single compressed air supply line or two compressed air supply lines of different pressures, as described in patents US6199360 and IT1412651 of the same owner.

Alternative embodiments are not excluded, wherein, for example, the compressed air injection means comprise one or more solenoid valves arranged along the compressed air supply line(s), instead of or in addition to the mechanical distribution valve.

Inside the hollow body 2, a control drum 18 is rotatably supported about its longitudinal axis, on the outer shell of which a set of peripheral cam tracks is obtained.

The control drum 18 includes at least:

a first cam track 19 for controlling the movement of the movable members of the locking clamp 12 and the cutting scissors 13 towards either end of the splicing chamber 5;

a second cam track 20 for controlling the movement of the movable members of the locking clamp 11 and the cutting scissors 14 at the other of the opposite ends of the splicing chamber 5.

In the embodiment shown in the figures, in which the

preparation devices

7,8 and the compressed air injection means in the splicing chamber 5 comprise a single distribution valve 17 mechanically controlled by the same control drum 18, the set of cam tracks comprises a third cam track 21 for controlling the spools of the distribution valve 17.

However, alternative embodiments are not excluded in which the slide valve 17 is not controlled by the control drum 18, or it is replaced by one or more solenoid valves.

An end portion of a cam follower pin extends along each cam track, each cam follower pin being provided at an end portion with a respective control rod, the opposite end portion of which acts on the respective member controlled by it.

In the drawings:

the ends of cam follower pins 22 extend along first cam tracks 19 and are arranged at the ends of respective control rods 23, the opposite ends of which act on the movable members of clamp 12 and cutting shears 13;

the ends of the cam follower pins 24 extend along the second cam track 20 and are arranged at the ends of respective control rods 25, the opposite ends of which act on the movable members of the clamp 11 and of the cutting shears 14;

the end of the cam follower pin 26 extends along the third cam track 21 and is provided at the end of a control rod 27, to which the opposite end of the spool of the distribution valve 17 is coupled.

The control of the opening and closing of the lid 6 can be taken care of by corresponding control means, of the mechanical or pneumatic type, also coming from the same dispensing valve 17.

Note that in the illustrated embodiment, each of the cam tracks 19, 20 and 21 has a linear development without a bifurcation, split or bypass portion.

The control drum 18 can be coupled, by means of suitable transmission members 28 (fig. 3 and 4), to a respective main drive motor 29 (schematically illustrated in the figures) accompanying each winding station 101.

The main drive motor 29 is advantageously a motor, preferably of the step-and-reverse type, controlled by the electronic control unit 200.

According to the invention, the

tie rods

9, 10 are not operated by means of the control drum 18 and the associated main drive motor 29, but by separate and independent or autonomous drive units, so that the movement of the

tie rods

9, 10 can be controlled during the entire splicing cycle and at any time outside the splicing cycle, in any direction and for any variable number.

For this purpose, the device 1 comprises a drive motor 30 for driving the movement of the

tie rods

9, 10 only, which is mounted on the hollow body 2 (on one of the two side walls 3 in the figures) and is provided with an angular position sensor 300. Means 31 for transmitting the movement from the drive motor 30 to the

tie rods

9, 10 are also provided, which are housed in the hollow body 2.

The drive motor 30 is separate and independent from the main drive motor 29.

The drive motor 30 is an electric motor.

The drive motor 30 is preferably a stepper motor, advantageously a reversible motor, which is fitted with an angular position sensor 300. The electronic command to the drive motor 30 and the control of said drive motor can be issued by the electronic control unit 200 not only on the basis of the splicing cycle and therefore on the basis of the movement of the other components of the apparatus 1, which are operated by the main drive motor 29, but also on the basis of the processing cycle (winding) and of the components accompanying the winding station 101, such as the rotary drum 105, the head support bar 106 and the related drive motors, the

rotatable arms

108, 109.

To this end, an angular position sensor 300 (in practice an encoder) is coupled to the drive motor 30.

Thanks to the provision of a drive unit (i.e. the drive motor 30 and the associated transmission member 31) for driving the

tie rods

9, 10 separate and independent from the drive units of the remaining movable members of the drive device 1 (i.e. the main drive motor 29 and the associated control drum 18 and any possible solenoid valves), the

tie rods

9, 10 can be moved from a rest position or "zero" position to any one or more working positions for performing splicing cycles or even for restoring the processing at the respective winding stations 101 for a desired and adjustable time.

The transmission member 31 comprises a gear train which transmits motion from the drive motor 30 to one of the two

tie rods

9, 10 and from said one tie rod to the other of the two

tie rods

9, 10.

Referring to fig. 5, the transmission member 31 includes a gear 32 splined to the output shaft of the drive motor 30 and meshing with a first sector gear 33 fixed to the end of a drive shaft 34, at which the end of one of the two tie rods (tie rod 10 in the figure) is also fixed. At the opposite end of the drive shaft 34 there is fixed a second sector gear 35 which meshes with a third sector gear 36 formed in one piece at one end of another tie rod (9 in the figures) which is rotatably supported by means of a pin 37 splined to the hollow body 2. The drive shaft 34 is rotatably supported by the hollow body 2.

There is also a reference stop 38 for at least one rest position of the

tie rods

9, 10 coupled to the hollow body 2. The stop 38 is a mechanical stop, for example made up of a pin fixed to the hollow body 2, against which one of the two tie-rods (in the figures the tie-rod 9) rests in a rest or "zero" position (i.e. in a position in which it starts its stroke without intercepting the respective thread end).

It is clear to a person skilled in the art that the drive motor 30 and the main drive motor 29 are controlled by the electronic control unit in a coordinated manner according to the type of splicing cycle to be performed.

With reference to the accompanying figures 12 to 21, the operation of the apparatus 1 and the method of pneumatic knotless splicing of yarn ends or thread ends that can be carried out with said apparatus 1 will now be described.

In general, the splicing method according to the invention comprises the following steps:

-introducing the ends of the yarn or ends of yarn CR, CS to be spliced into the splicing chamber 5;

locking the ends of the yarns CR, CS entering the splicing chamber 5 with the locking clamps 11, 12;

cutting off the ends of the thread or ends CR, CS exiting from the splicing chamber 5 with cutting

scissors

13, 14;

-sucking in the ends of the thread-ends CR, CS cut in the

preparation devices

7,8 by means of injecting compressed air into said devices and preparing the ends of the sucked-in thread-ends CR, CS by means of injecting compressed air into the

preparation devices

7,8 through the compressed air injection devices (distribution valves 17);

the cut and prepared ends of the thread ends CR, CS are withdrawn in the direction of the splicing chamber 5 by means of the draw-

rods

9, 10, which are thus operated from their rest position to their at least one working position;

splicing of the ends of the yarn CR, CS is carried out by injecting compressed air into the splicing chamber by means of a compressed air injection device (distribution valve 17), said ends of the yarn CR, CS being withdrawn into the splicing chamber 5 placed side by side and partially overlapping.

After the step of introducing the ends of yarn CR, CS to be spliced into the splicing chamber 5 and before the step of locking the ends of yarn CR, CS entering the splicing chamber 5 with the locking clamps 11, 12, a step of closing the longitudinal slot of the splicing chamber 5 by means of the cover 6 can be provided.

In this case, at the end of the splicing step, a step is provided which comprises opening the longitudinal slot of the splicing chamber 5 by moving the cover 6 away from the longitudinal slot of the splicing chamber.

According to the invention, just as the operation of the tie-

rods

9, 10 has been decoupled from the operation of the remaining movable members of the apparatus 1, the splicing method can also comprise at least one of the following steps:

a) After the step of sucking the cut end of the thread end or ends CR, CS into the preparing

device

7,8, the

levers

9, 10 are operated from their rest position to their working position to intercept the thread end or ends CR, CS in the direction of withdrawing the end of said thread end or ends sucked into said preparing device from the preparing

device

7,8 and then the

levers

9, 10 are operated in the direction of returning the

levers

9, 10 to their rest direction to release the end of said thread end or ends in the direction of inserting the thread end or ends into the preparing

device

7,8 during the injection of compressed air for preparing said end;

b) Operating the

levers

9, 10 from their rest position to their working position, after the step of sucking the cut ends of the thread ends CR, CS into the preparing

devices

7,8 and during the introduction of compressed air into said preparing devices for preparing the ends of the thread ends CR, CS sucked therein, to intercept said thread ends CR, CS in a direction of extracting the ends of the thread ends CR, CS sucked therein and being prepared from the preparing

devices

7, 8;

c) During the step of withdrawing the ends of the yarns prepared and cut by the

preparation devices

7,8 in the direction of their insertion into the splicing chamber 5, compressed air is injected into the splicing chamber 5;

d) After the splicing step (and after possible opening of the splicing chamber 5 by removing the cover 6): the ends of the yarn thus spliced are released by opening the locking clamps 11, 12, while keeping the

tie rods

9, 10 in the working position; and operating the

levers

9, 10 by returning them to their rest position, simultaneously releasing the spliced yarn from the apparatus 1 and thus simultaneously resuming the treatment (winding) of the yarn thus spliced in the relative work position;

e) After the splicing step (and after possible opening of the splicing chamber 5 by the cover 6): the ends of the yarn thus spliced are released by opening the locking clamps 11, 12, while the

tie rods

9, 10 are held in the working position; operating the draw-

rods

9, 10 to make an additional stroke in the direction of introducing the thread ends into the splicing chamber 5, recovering the excess thread released by the locking clamps 11, 12; and operating the

levers

9, 10 to return the

levers

9, 10 to their rest position, releasing the spliced yarn from the apparatus 1 and thus resuming the processing (winding) of the yarn thus spliced in the relative work station.

As will be immediately understood by the skilled person, the above-mentioned steps a) and b) are mutually alternative and allow to move the thread ends CR, CS along the preparing

devices

7,8 during the preparing step (i.e. while injecting compressed preparing air therein) after the ends of the thread ends CR, CS have been cut and sucked into the preparing

devices

7, 8.

Step a) is of the so-called "out-in" (out-in) type: each thread end is captured by the respective preparing

device

7,8 by means of an initial suction jet (pre-blow), then by extracting the end of the thread end sucked into the preparing

device

7,8, the

respective tie rod

9, 10 intercepts the thread end until it is brought into the inlet of the preparing device itself, after which by injecting the jet(s) of compressed preparing air (preparing blow) into the preparing device, the

respective tie rod

9, 10 is brought back to its rest position, so as to reintroduce the end of the thread end into the respective preparing

device

7,8 during the preparing step.

Step b) is of the so-called "in-out" (in-out) type: the draw-

rods

9, 10 are operated to intercept the thread ends whose cut ends have been sucked into the

preparation devices

7,8, while the jet(s) of preparation compressed air are injected into said preparation devices. The ends of the thread ends are then drawn out of the

preparation devices

7,8, while they are pneumatically prepared.

Steps a) and b) make it possible to optimize the preparation of the end of the thread ends to be spliced according to the different types of yarn.

The preparation blow can be performed several times within a predetermined time (all of which can be set by the PC), whether during step a) or b) or during the regular preparation step.

Step c) enables the intended injection of the splicing compressed air jet into the splicing chamber 5 before the end of the step of withdrawing the cut and prepared yarn end into the splicing chamber 5.

At the end of the step of withdrawing the ends of the threads CR, CS into the splicing chamber 5, performed by the

tie rods

9, 10, one or more jets of splicing compressed air can be injected into the splicing chamber 5 for a predetermined number of times.

Steps d) and e) are carried out at the end of each splicing cycle and are controlled by the electronic control unit 200 in such a way that they can be coordinated with the resumption of the yarn treatment (for example winding) at the respective treatment station (for example winding station) so as to prevent the spliced yarn from being suddenly released and/or jumped or vibrated, as a result of which the clearer 104 can generate false intervention signals to remove defects and/or the yarn can collide with parts of the apparatus 1, damaging them.

Thanks to the angular position sensor 300, the electronic control unit 200 knows exactly the position of the drive motor 30 and therefore of the

tie rods

9, 10 and during each splicing cycle it coordinates the operation of the drive motors 30 of the

tie rods

9, 10 with the operation of the main drive motor 29, for example the operation of the drive motors 30 of the

tie rods

9, 10 with the operation of the motors 107 of the head support bar 106 and of the motors of the winding drum 105 and with the other movable parts (in particular the rotatable arms 108, 109) of each work station (winding station) during the step of restarting the treatment (winding) at the end of each splicing cycle.

In particular, the electronic control unit 200 controls the operation of the drive motor 30 during the above-mentioned step e) to make the

tie rods

9, 10 perform an additional stroke in the direction of introduction of the thread end into the splicing chamber 5, so as to recover the excess thread released by the locking clamps 11, 12 in synchronism with the restart of the rotation of the rotary drum 105 and the return of the end support rod 106 to its rest position. The operation of the

tie rods

9, 10 for this additional stroke makes it possible to keep the tension of the spliced yarn constant during the restart of the processing (winding) step, while guaranteeing the normal slipping of the yarn (for this purpose, the speed of movement of the tie rods during this additional stroke is adjusted according to the set acceleration of the rotary drum 105 and the return speed of the head support bar 106).

The subsequent operation of the

levers

9, 10 in opposite directions for returning them to their rest position is such that the spliced yarn does not vibrate in the clearer 104 or jump due to slow contact with parts of the device 1.

Steps d) and e) enable the controlled release of the spliced yarns to be carried out at the end of each splicing cycle in coordination with the resumption of the yarn treatment at the respective work station.

Furthermore, according to the invention, it is possible to perform a so-called "self-calibration" cycle of rest or zero position of the draw-

rods

9, 10, without any manual intervention, each time the textile machine (winder) 100 and/or each winding station 101 thereof is switched on (or following a special PC command applied and/or according to the operator requirements or to the change of the yarn batch being processed and/or to remove the complete package set-up and/or to reduce possible errors.

The cycle of "self-calibrating" or finding the rest or zero position of the

tie rods

9, 10 comprises the following steps:

operating the drive motor 30 to rotate the

tie rods

9, 10 until one of them intercepts the stop 38 with which it collides;

detecting the angle at which the collision occurs between the tie-

rods

9, 10 and the stop 38 by means of the angular position sensor 300;

operating the drive motor 30 in the opposite rotational direction to move the

tie rods

9, 10 away from the stop 38;

-repeating the above steps n times to confirm the detected collision angle, wherein n ranges from 1 to 10;

after determining the impact angle, operating the drive motor 30 to cause the

tie rods

9, 10 to perform a predetermined stroke (for example, corresponding to 5 °) controlled by the angular position sensor 300, so as to position themselves in the rest or "zero position" or in the starting position in which the angular position sensor 300 will be configured as "0 °".

Fig. 12 to 21 show in sequence the different steps of the development of the splicing cycle with the recovery process (winding 101) at the work station:

when the electronic control unit 200 receives a signal that the device 1 of the winding station 101 has to splice two yarn ends, the electronic control unit 200 controls the

rotatable arms

108, 109, the head support bar 106 and the corresponding motor 107, the main drive motor 29 and the drive motor 30 of only the

tie rods

9, 10 to perform the following steps:

-introducing the two ends of yarn CR and CS into the splicing chamber 5 by means of the rotatable arms 108, 109 (fig. 12);

bringing the cover 6 into the closed position of the splicing chamber 5 (figure 13);

closing the locking clamps 11, 12 in order to lock the portion of the yarn ends CR, CS entering the splicing chamber 5 (fig. 14); in this step, the draw-

rods

9, 10 can be operated so that they have entered the yarn ends CR, CS without however changing their course;

operating the cutting

scissors

13, 14 to cut the ends of the ends CR, CS of the thread leaving the splicing chamber 5 (figure 15);

-sucking the ends of the thus cut ends of yarn CR, CS into a

preparation device

7,8, in which the ends of the yarn CR, CS are pneumatically opened and/or untwisted (figure 16), by one of the methods described for carrying out steps a) and b) in which the

tie rods

9, 10 are involved;

-pulling the ends of the prepared ends of yarn CR, CS out of the

preparation devices

7,8 and withdrawing them back into the splicing chamber 5 by means of the

tie rods

9, 10, to the desired overlap length determined by the predetermined displacement exerted on the

tie rods

9, 10 by the drive motor 30 (fig. 17);

the end splices of the ends of the yarn ends CR, CS in the splicing chamber 5 are withdrawn by injecting jets of compressed air into the splicing chamber 5, which can also be controlled and/or can be repeated during the last phase of the above withdrawal step, depending on the yarn type (fig. 18);

opening the lid 6 and the locking clamps 11, 12, keeping the

tie rods

9, 10 in position (fig. 19); this advantageously occurs in synchronism with a command to restart the rotary drum 105 (fig. 19);

with the restart of the rotary drum 105, the

tie rods

9, 10 exert an additional stroke in the direction of withdrawal of the spliced yarn into the splicing chamber 5 to recover the excess spliced yarn released by the locking clamps 11, 12;

upon resumption of winding or in any case of treatment of the spliced yarn, the latter is released from the device 1, which is accompanied by the control of the return of the

tie rods

9, 10 to their rest or zero position, so as to release the spliced yarn from the device 1 in a controlled manner, avoiding vibrations and jumps (figure 21).

Fig. 11 shows a planar developed superimposition (solid line with sectional markings) of the cam path of a control drum 18 according to the invention, which is superimposed on the cam path of a control drum according to the prior art with motion reversal (hatched line).

It has to be noted that there are only three cam tracks in the control drum 18, respectively a first cam track 19, a second cam track 20 and a third cam track 21, each of which has a linear development without a bifurcation or split or bypass.

On the other hand, in the control drum according to the prior art, there is a fourth control track T4 with a notch or step section for controlling the tie-rods for various preset strokes according to the withdrawal length of the thread end in the desired splicing chamber. Furthermore, in the control drum according to the prior art, the control track of the dispensing valve must comprise two branch portions, one of which is a forward portion for controlling the preparation of the blow and the other is a return portion for controlling the splice blow.

It is apparent that the cam tracks of the control drum 18 according to the invention have a smaller angular spread than the control drums of the prior art. Furthermore, since the

drawing rods

9, 10 are controlled by separate and independent drive units dedicated to them, the movement of said

drawing rods

9, 10 can be controlled at any time, to any extent and for any time duration, enabling the adjustment of the overlapping length of the ends of the thread ends withdrawn in the splicing chamber without the constraints imposed by the notches or steps of the fourth cam track T4, the movement of which is controlled according to the prior art.

It must then be noted that, since a drive unit is provided only for the

tie rods

9, 10, which is separate and independent of the operation of the remaining movable components of the apparatus 1 (the control drum 18 and the relative main drive motor 29), the "down time" for reversing the rotation of the control drum, which is necessary according to the prior art to control the dispensing valve in the direction of injection of the jet of compressed air into the splicing chamber, is eliminated, thus increasing the immediacy between the end of withdrawal and the splicing blow.

In practice it has been determined that the invention achieves the preset aims.

Since there is provided a drive unit (drive motor 30, angular position sensor 300 and transmission member 31) for moving the

tie rods

9, 10, which is separate and independent from the drive unit of the remaining movable members of the apparatus 1 (control drum 18 and main drive motor 29), it is able to:

the degree of integration and communication between the device 1 and the movable members of the textile machine (winder) on which said device is mounted, including the suction rotating arm, the head support bar, the rotating drum, is improved, with the result of reducing the time of a complete splicing cycle (between clear cut and winding restart commands). This is the case, for example, during the step of unwinding the spliced yarn and resuming its processing (winding).

-reducing the tolerance of the overlapping size of the yarn ends in the withdrawal splicing chamber by more than 50%, thereby improving the quality of the splicing.

Automating the procedure for calibrating the rest or zero position of the tie rod, eliminating the errors caused by manual and uncontrolled calibrations and thus improving the quality of splices, as well as simplifying and reducing the equipment assembly, testing and maintenance operations since the position of the current tie rod is always known.

Since the

tie rods

9, 10 can be controlled continuously and unrestrictedly by an adjustable displacement (for example, the restriction imposed by the notches or steps of the cam track dedicated to this purpose in the prior art), the withdrawal and overlap lengths of the ends of the thread ends in the splicing chamber can be freely adjusted according to the type of thread, thus improving the splicing quality.

The maintenance and replacement operations of the group consisting of the tie rod are simplified, the drive unit of the tie rod being in fact an independent and self-aligning unit.

Increase versatility of use of the device with different types of yarn.

-reducing the total time of each complete splicing cycle by about 20-25% compared to the time of a complete splicing cycle according to the prior art in which there is a reversal of the rotation of the control drum.

Integrating the operability of the device 1 with that of the textile machine (winder) mounted on said device. As we have seen, the movement of the tie-rod can be controlled even at the end of each splicing cycle so as to apply a desired level of tension to the spliced yarn during its release, in a synchronous manner or in any case in a manner coordinated with the recovery of the treatment (winding) of the spliced yarn, so that it is possible to prevent the spliced yarn from vibrating and/or jumping, thus eliminating the splicing cycle and the damage to the pieces of equipment (damage due to jumping of the spliced yarn released at the recovery treatment) due to erroneous intervention by the clearer (which can detect vibrations as a defect and therefore intervene even when not necessary).

Furthermore, as mentioned above, the apparatus according to the invention allows to implement a splicing method in which, thanks to the fact that the operation of the tie-rod has been made autonomous and independent of the control drum responsible for controlling the air distribution valve(s) for the preparation device and the splicing chamber:

the withdrawal step of the yarn ends in the splicing chamber overlaps with the step of the splicing step (injecting air into the splicing chamber).

-performing a differentiated preparation step according to the yarn type. In fact, even the injection into the preparation device of one or more jets of only sucked and/or prepared compressed air can be controlled and maintained for different times, based on different positions of the end of the sucked-in thread ends ("multiple blow" or "multipoint" preparation) and/or on different lengths of the end of the thread ends sucked therein, with the result that the quality of the splice is improved in terms of appearance and strength and quality parameters (CV%), the different positions of the end of the sucked-in thread ends and/or the different lengths of the end of the thread ends sucked therein can be varied during the execution of the preparation step by means of the preparation blow ("in-out" or "out-in" preparation) due to the independent control of the movement of the draw rod.

The device according to the invention therefore has a flexible and repeatable operation and operability and eliminates the need for manual mechanical calibration of the rest position of the tie rod, avoiding interventions and errors affecting the quality of the splice.

Finally, the apparatus according to the invention allows to perform splicing cycles without having to reverse the rotary motion of a dedicated control drum for the operation of the remaining components of the apparatus itself, thus reducing the execution times and improving the control precision as regards the angular position of the control drum and the position of the control rod moved by the control drum, including in particular the control rod of a sliding distribution valve for distributing jets of compressed air to the preparation device and to the splicing chamber. Once the inevitable coupling clearances between the control drum and its main drive motor and associated transmission members and between its cam tracks and the respective control levers operated by them in the first splicing cycle are cleared, these clearances will no longer occur, since there is no need to reverse the direction of rotation of the control drum.

The device for knotless pneumatic splicing of yarns or thread ends, mounted on a textile machine, in particular on an automatic winder equipped with an electronic control unit designed for this purpose, is susceptible of numerous modifications and variants, all of which are within the scope of the present invention; moreover, all the details may be replaced with technically equivalent elements. In practice, the materials used, as well as the dimensions, may be of any type according to the technical requirements.

Claims

1. Device (1) for the pneumatic knotless splicing of yarn ends or stubs to be mounted on a textile machine, in particular on an automatic winder (100) equipped with an electronic control unit (200), comprising:

-a hollow body (2) supporting a splicing chamber (5) provided with lateral openings opposite each other, between which a longitudinal slot extends, which is open at the top for the introduction therein of two ends of yarn or threads to be spliced,

-preparation means (7,8) for the pneumatic preparation of the ends of the threads or ends to be spliced, mounted on the hollow body (2) at a distance from the opposite lateral opening of the splicing chamber (5),

-a locking clamp (11, 12) for locking the ends of the yarn or threads introduced into the splicing chamber (5), mounted on the hollow body (2) at a distance from the opposite lateral opening of the splicing chamber (5);

-cutting scissors (13, 14) for cutting off the ends of the thread or ends of the thread exiting from the opposite lateral openings of the splicing chamber (5), mounted on the hollow body (2) at a distance from the opposite lateral openings of the splicing chamber (5);

-tie rods (9, 10) for withdrawing the yarn ends or the ends of the yarn ends from the preparation device (7,8) towards the splicing chamber (5), mounted on the hollow body (2) at a distance from the opposite lateral opposite openings of the splicing chamber (5);

-compressed air injection means for injecting compressed air into the preparation means (7,8) and the splicing chamber (5);

-a control drum (18) housed inside said hollow body (2) in a rotatable manner about its longitudinal axis and comprising a peripheral set of cam tracks having at least a first cam track (19) and a second cam track (20) for controlling the movement of the locking clamps (11, 12) and of the movable members of the cutting scissors (13, 14), wherein said control drum (18) is couplable to a main drive motor (29) mounted on the textile machine (100);

characterized in that the device comprises

-a drive motor (30) driving the movement of the tie rods (9, 10) only, said drive motor (30) being mounted on the hollow body (2) and being coupled with an angular position sensor (300) and with a transmission member (31) for transmitting the movement from the drive motor (30) to the tie rods (9, 10) housed in the hollow body (2), wherein the drive motor (30) is separate and independent with respect to the main drive motor (29).

2. Device (1) according to claim 1, characterized in that the drive motor (30) only for driving the movement of the draw rods (9, 10) is an electric motor, preferably an electronically controlled stepping electric motor.

3. Apparatus (1) according to any one of the preceding claims, characterized in that said transmission member (31) comprises a gear train which transmits the motion from said drive motor (30) to one of the two tie rods (9, 10) and from said one tie rod to the other tie rod of said two tie rods (9, 10).

4. The apparatus (1) according to one or more of the preceding claims, characterized in that it comprises a reference stop (38) for defining at least one rest position of said tie-rod (9, 10) and which is coupled to said hollow body (2).

5. The apparatus (1) according to one or more of the preceding claims, characterized in that said compressed air injection means comprise at least one sliding distribution valve (17) housed inside said hollow body (2), wherein said set of cam tracks comprises at least a third cam track (21) for controlling the sliding of the spool of said sliding distribution valve (17).

6. Device (1) according to claim 5, characterized in that said set of cam tracks comprises only three cam tracks: a first cam track (19) for controlling a movable member of one of the locking clamps (11, 12) and one of the cutting scissors (13, 14); a second cam track (20) for controlling the movable members of the other of the locking clamps (11, 12) and of the other of the cutting scissors (13, 14); -third cam tracks (21) for controlling the sliding of the spools of the sliding distribution valve (17), wherein each cam track has a linear development.

7. Method for knotless pneumatic splicing of yarn ends or thread ends, which can be carried out with a device (1) according to one or more of the preceding claims, to be mounted on a textile machine (100), in particular on an automatic winder equipped with an electronic control unit (200), comprising the steps of:

-introducing the ends of the yarn or threads to be spliced (CR, CS) into the splicing chamber (5);

-locking the end of yarn or thread (CR, CS) entering the splicing chamber with the locking clamp (11, 12);

-cutting off the end of the thread or ends (CR, CS) exiting from the splicing chamber (5) with the cutting scissors (13, 14);

-sucking the end of the cut yarn end or ends (CR, CS) into the preparing device (7,8) by means of injecting compressed air into the preparing device and preparing the sucked end of yarn end or ends by injecting compressed air into the preparing device (7,8) by the compressed air injecting device;

-withdrawing the cut and prepared end of the thread or thread ends (CR, CS) in the direction of the splicing chamber (5) by means of the draw-rods (9, 10) operated by the drive motor (30);

-performing a splicing of the ends of the yarn ends or ends (CR, CS) by injecting compressed air into the splicing chamber (5) by the compressed air injection means;

characterized in that the method further comprises at least one of the following steps:

a) -after the suction step of sucking the cut end of the yarn or thread end (CR, CS) into the preparation device (7,8), operating the draw bar (9, 10) to intercept the yarn or thread end (CR, CS) in the direction of withdrawing the end of the yarn or thread end (CR, CS) sucked into the preparation device from the preparation device (7,8) and subsequently releasing the yarn or thread end (CR, CS) in the direction of inserting the end into the preparation device (7,8) during the injection of compressed air into the preparation device (7,8) for preparing the end;

b) -operating the draw bar (9, 10) to intercept the yarn end or thread end (CR, CS) following a suction step of sucking the cut end of the yarn end or thread end (CR, CS) into the preparation device (7,8) and during the injection of compressed air into the preparation device (7,8) for preparing the end of the yarn end or thread end (CR, CS) sucked into the preparation device, in a direction of withdrawing the sucked end of the yarn end or thread end from the preparation device (7,8) and during a pneumatic preparation step thereof;

c) Injecting compressed air into the splicing chamber (5) by means of the compressed air injection means during the step of withdrawing the end of the cut and prepared yarn or thread ends (CR, CS) in the direction of the splicing chamber (5);

d) After the splicing step: -retaining the tie rod (9, 10) in the working position by releasing the yarn end or ends thus engaged by opening the locking clamp (11, 12); and operating the draw bar (9, 10) during the release of the spliced yarn or thread from the apparatus (1) to bring it back to its rest position for resuming the processing of the spliced yarn or thread;

e) After the splicing step: -releasing the thus spliced thread ends or ends by opening the locking clamps (11, 12), keeping the tie-rods (9, 10) in the working position; -operating the draw-rod (9, 10) for an additional stroke in the direction of introduction of the spliced thread ends or stubs into the splicing chamber (5), recovering the excess thread or thread released by the locking clamp (11, 12); and operating the draw bar (9, 10) during the step of releasing the spliced yarn or thread from the apparatus (1) to bring it back to its rest position for restoring the treatment of the spliced yarn or thread.

8. Method according to claim 7, comprising a step of calibrating the rest position of the tie-rods (9, 10) before the splicing cycle, the step of calibrating comprising the steps of:

-operating the drive motor (30) of the tie rods (9, 10) to rotate the tie rods (9, 10) until one of them intercepts a mechanical stop (38) colliding with it;

-detecting the angle at which a collision occurs between the tie-rod (9, 10) and the stop (38) by means of the angular position sensor (300) coupled with the drive motor (30) of the tie-rod (9, 10);

-operating the drive motor (30) in opposite rotational directions to move the tie rods (9, 10) away from the stop (38);

-repeating the preceding steps n times to confirm the detected collision angle;

-after determining the impact angle, operating the drive motor (30) to cause the tie-rods (9, 10) to perform a set stroke controlled by the angular position sensor (300) so as to position them in a position corresponding to the angular position sensor (300) configured as zero, considered as a rest position for the tie-rods (9, 10).