WO2023073229A1

WO2023073229A1 - A method of cutting off an end part of yarn before resuming the spinning process on a textile machine for producing yarn, a device for performing the method and a textile machine for producing yarn

Info

Publication number: WO2023073229A1
Application number: PCT/EP2022/080367
Authority: WO
Inventors: Marek JAKUB
Original assignee: Maschinenfabrik Rieter Ag
Priority date: 2021-11-01
Filing date: 2022-10-31
Publication date: 2023-05-04
Also published as: CZ2021500A3

Abstract

The invention relates to a method cutting off an end part of yarn (8) before resuming the spinning process on a textile machine for producing yarn (8), in which the yarn (8), after spinning has been interrupted, is first guided to an outlet (200) of the yarn (8) from a spinning device (20) and subsequently, the yarn (8) is cut by a cutting device (1) to form the end of the yarn (8) to be introduced into the spinning device (20), and the end of the yarn (8) thus formed is subsequently introduced into the spinning device (20) to resume spinning. Before interrupting the yarn (8) for forming the end of the yarn (8) to be introduced into the spinning device (20), mechanical energy which is necessary for cutting the yarn (8) is accumulated in the cutting device (1) and this accumulated mechanical energy for interrupting the yarn (8) is released in one single step, thereby obtaining energy for the drive of the cutting device (1) to form the end of the yarn (8) for introduction into the spinning device (20). The invention also relates to a device for cutting off an end part of yarn (8) before resuming spinning on a textile machine for producing yarn (8) and to a textile machine for producing yarn (8).

Description

A method of cutting off an end part of yarn before resuming the spinning process on a textile machine for producing yarn, a device for performing the method and a textile machine for producing yarn

Technical field

The invention relates to a method of cutting off an end part of yarn before resuming the spinning process on a textile machine for producing yarn, in which the yarn, after spinning has been interrupted, is first guided to an outlet of the yam from a spinning device and then the yarn is cut by a cutting device to form the end of the yarn to be introduced into the spinning device, and the end of the yam thus formed is then introduced into the spinning device to resume spinning.

The invention also relates to a device for cutting off an end part of yam before resuming the spinning process on a textile machine for producing yam, which comprises a cutting device which is adjustable between its rest position and its cutting position, wherein the cutting device is provided with a mechanism for interrupting yam which is connected to a source of its motion for cutting the yam.

In addition, the invention relates to a textile machine for producing yam comprising a plurality of workstations arranged next to each other in at least one row, wherein each workstation comprises unit automation devices for resuming the yam production and further comprises a yam cutting device to form the end of the yam to be introduced into a spinning device.

Background art

In textile machines producing yam, especially in rotor and air-jet spinning machines, yam production is interrupted either for technological reasons or due to the detection of a yam quality defect, which is detected by a yam quality sensor directly during the yam production.

When the yam production is interrupted, the end of the yam is often or usually wound onto a bobbin. In order to resume the yam production, it is first necessary to find the end of the yam on the bobbin, which is usually carried out by a suction nozzle that is either fixed or movable. Depending on the reason for the interruption in the yarn production (e.g., the yarn does not meet the required quality parameters along a certain length), the detected end of the yarn is removed in the required length before resuming spinning (spinning-in). By this removal, a new end of the yarn is created, which is optionally further transformed into the form of a spinning-in end of the yarn for the subsequent resumption of spinning, i.e., for the subsequent resumption of the yam production.

For the actual resumption of yam production on spinning machines, i.e., resumption of the spinning process, it is necessary to introduce the newly created end of the yam into an outlet of a spinning device. This operation usually requires the above-mentioned treatment of the end of the yam in a specific way so that the above-mentioned introduction of the yam is carried out with a high success rate. A suitable treatment of the yam end for its highly successful introduction into the outlet of the spinning device is usually the treatment of the yam end by cutting the yam, or by cutting off the excess part of the end length of the yam. Spinning machines for the production of yam, whether rotor machines or air-jet machines, which comprise a row of identical workstations for the production of yam which are arranged next to each other, are often provided with unit automation devices for the resumption of spinning, the so-called spinning-in automation devices, which increases the efficiency of the use of the machine, as there is no time loss due to waiting for the arrival of a service robot at the relevant spinning station. These spinning machines are able to restart the spinning process both after a natural yam break and after a yam break caused by insufficient yam quality sensed by the yam quality sensor by means of the unit automation devices. The broken end of the yam which is wound onto the bobbin and lies on the surface of the bobbin, is found by the suction nozzle after stopping the workstation. The required length of the yam end is unwound and cut off to form the spinning-in end of the yam which is brought above the spinning device and introduced into the outlet of the spinning device. This procedure is described in detail for rotor spinning machines in various variants, for example in US 4,494,371 or GB 1 ,306,232, and for an air-jet spinning machine, for example, in US 5,419, 110.

Furthermore, numerous documents are known from the patent literature which disclose a method of yam spinning-in, especially on rotor spinning machines which include a cutting device for cutting off the end part of the yarn before spinning-in. US 4 653 260 or DE 3 418 780 describe that, after cutting off the end of the yam, the newly formed end of the yarn is subsequently exposed to air flow to improve the conditions for successful spinning-in. However, these documents do not describe a specific device for cutting the end of the yarn.

A solution according to US 4246 749 also implies the use of a mechanism for cutting off the end of the yarn, again without describing in detail the construction and function of this mechanism for cutting off the end of the yam.

US 4 114 356 and GB 1 497 391 disclose a yam cutting mechanism which is powered by compressed air and which is controlled by means of an air valve.

For air-jet spinning machines, a solution is known in which, after the workstation has stopped after a yam break indicated by a yam quality sensor or even after a natural yam break at the workstation, a lever for capturing the yam is first moved from a lower parking position to tan upper position, where it seals a slot of a suction nozzle for searching the end of the yam on a bobbin. A vacuum source is then activated and the suction nozzle linearly approaches the surface of the bobbin with the wound end of the broken yam. The bobbin starts rotating in the opposite direction to the yam winding direction in the yam production, and the end of the yam from the surface of the bobbin is sucked into the suction nozzle. Subsequently, the end of the yam is caught in a yam catcher on the lever for capturing the yam and this lever is rotated back to its lower position. During this motion of the lever for capturing the yam, the yam is inserted into a yam break sensor, is moved under a yam pressure roller of a yam draw-off mechanism, is introduced into a yam quality sensor, and is also inserted into a yam cutting device, the so-called yam cutter. Subsequently, the yam is cut by the yam cutting device and air flow in a spinning nozzle is activated, which causes a vacuum in the outlet of a spinning device, thereby sucking the end of the yam formed by the above-described cutting operation into the spinning nozzle. The disadvantage of the above-mentioned solution is that the energy required to cut the yam must be generated by an independent source, either pneumatic or electric, which increases the cost of the solution and that makes the design, mounting and maintenance of the spinning machine rather complicated. US5083420A discloses a device for piecing yarn, which includes a rotary yam mover to which a yarn cutting device is assigned that includes a roller assigned to a cutting edge that is coupled to an actively controlled drive. The control drive consists of a drive that requires an external energy supply to carry out the piecing of the yarn and does not comprise any mechanical energy accumulator for the piecing of the yarn.

CS 241423 discloses a device for piecing yam which comprises mechanically controlled scissors, wherein the opening of the scissors is controlled by actively inserting a wedge between the end arms of the scissors and the cutting motion of the scissors is actively controlled by sliding a wedge groove on the outer sides of the end arms of the scissors. The device for piecing yam does not include a mechanical energy accumulator for piecing the yam.

The object of the present invention is to eliminate or at least minimize the disadvantages of the background art.

Summary of invention

The object of the invention is achieved by a method of cutting off an end part of yam before resuming spinning on a textile machine for producing yam, whose principle consists in that before the yam is interrupted to form the end of the yam to be introduced into a spinning device, the mechanical energy required to interrupt the yam is accumulated in a cutting device, and this accumulated mechanical energy is released in a single step to interrupt the yam, thereby obtaining energy to drive the cutting device to form the end of the yam to be introduced into the spinning device.

The principle of the device for cutting off the end part of the yam before resuming spinning on a textile machine for producing yam is that the source of the motion of the mechanism for interrupting the yam by the cutting device comprises at least one mechanical accumulator of mechanical energy, wherein the mechanism for interrupting the yam by the cutting device comprises at least one cutting knife and further comprises a force generator adapted for acting on the mechanical accumulator of mechanical energy, wherein the cutting knife is coupled to the mechanical accumulator of mechanical energy and is further coupled to a blocker of accumulated mechanical cutting energy, wherein the blocker is coupled to a control element for one-time releasing the accumulated mechanical cutting energy of the cutting device.

The principle of the textile machine for producing yarn consists in that the cutting device is formed according to any of claims 6 to 12.

The invention is based on the fact that the energy needed for cutting the yam and for forming the end of the yam to be introduced into the spinning device is generated by accumulating the energy of another part of the workstation in an accumulation member of the cutting device, e.g., in a spring-stretched swinging knife during the motion of the cutting device, e.g. , after previously cutting the yam. Subsequently, the accumulated energy is released to cut the yam according to the current requirements at the workstation, e.g., to cut the yam to form the end of the yam for introduction into the spinning device and before guiding this spinning-in end of the yam to the outlet of the spinning device for spinning-in, i.e., to resume spinning, i.e., to resume yam production. Ideally, it appears that if a yam handling mechanism after finding the yam on the bobbin and after takeover the found yam performs introduction of the yam into a yam quality sensor, further into a yam draw-off mechanism, further into a yam break sensor, further to the outlet of the yam from the spinning device, then for cutting the yam is sufficient for the yam cutting device to approach the spinning device, where it moves to a position in which the yam passes between the cutting edges of the cutting knives and in which the end of the yam for introduction into the spinning device is formed by the subsequent cutting , where this end of the yam is ready to be introduced into the spinning device to resume spinning. It is advantageous if the cutting device moves reciprocally linearly and at the same time parallel with the longitudinal axis of the spinning device, because then the cutting device is always in the same position towards the outlet of the yam from the spinning device. The linear motion of the cutting device by means of a suitable drive makes it possible to use different types of spinning device, wherein the distance to which the cutting device is set relative to the spinning device to carry out the yam cutting, see reference X in Fig. 5, can always be the same without any mechanical adjustment. The solution according to the invention also makes it possible to use one drive both for driving the linear reciprocating motion of the cutting device, and for controlling, activating and driving the cutting knives. This brings considerable cost reductions, simplifies and accelerates assembly and facilitates maintenance. In addition, the method of cutting the yam according to the invention eliminates the effect of mechanical clearances that occur in every mechanical device, in such a way that yam cutting is activated only when the respective blocker gets into contact with the adjacent wall of the spinning device, regardless of the current position of the other mechanisms and components of the workstation.

From the point of view of control of the entire process, it is advantageous for the cutting device to be provided with a suitable proximity sensor of the cutting device approach to the spinning device, or it is possible to detect this mutual approach in another suitable manner, for example by monitoring the increase in electric current or the performance taken by the drive of the cutting device via the control system of the workstation, etc.

Using the solution according to the invention will simplify the workstation of the textile machine, facilitate assembly and adjustment, reduce costs, increase reliability and eliminate the effects of unwanted mechanical clearances in the system.

Brief description of drawings

The invention is schematically represented in the drawings, wherein:

- Fig. 1 shows a typical arrangement of a workstation of an air-jet spinning machine during yam production;

- Fig. 1 a shows a detail of an arrangement of a workstation of an air-jet spinning machine after finding the end of the yam on a bobbin and its introduction into a spinning device;

- Fig. 2 shows the first phase of the operation of the device according to the invention, i.e. , the accumulation of energy for cutting the yam;

- Fig. 3 shows the second phase of the operation of the device according to the invention, i.e., the motion of the cutting device towards the outlet of the yam from the spinning device and guiding the yam between the knives of the cutting device; - Fig. 4 shows the third phase of the operation of the device according to the invention, i.e., the initialization of the yarn cutting and the yarn cutting operation itself;

- Fig. 5 shows linear motion of the cutting device in relation to the outlet of the yam from the spinning device.

Examples of embodiment

The invention will be described with reference to an exemplary embodiment at a workstation of an air-jet spinning machine, wherein an air-jet spinning machine comprises at least one row of workstations arranged next to one another. The implementation of the invention at the workstation of a rotor spinning machine is similar and for a skilled person in the field of spinning machines, knowledge of this description lies within the scope of the professional skill.

An air-jet spinning machine for producing (spinning) yam comprises a plurality of workstations arranged next to one another. Each workstation comprises a drafting device 21 of a sliver 210 which during the production of the yam 8 moves in the P direction, as shown in Fig. 1 .

In the P direction of the motion of the sliver 210, a spinning device 20 is arranged downstream of the drafting device 21 which includes un unillustrated spinning nozzle. The spinning device 20 is configured to transform the sliver 210 into yam 8 which subsequently exits the spinning device 20 through an outlet 200, wherein the yam is withdrawn from the spinning device 20 by a yam drawoff mechanism 13 which is arranged in the direction of the motion of the yam 8 downstream of the spinning device 20. The withdrawn yam 8 is subsequently wound onto a bobbin 24 by a yam winding device 10, where the bobbin 24 is rotatably mounted in a holder 100.

Between the spinning device 20 and the draw-off mechanism 13 is arranged a yam quality sensor 14, through which the yam 8 passes during its production. Between the draw-off mechanism 13 and the winding device 10 is arranged a yam presence sensor 12, through which the yam 8 passes during its production and before being wound onto the bobbin 24.

Each workstation is provided with a suction nozzle 11 , which is adapted to search for the end of the yam 8 wound on the bobbin, e.g., after the production of the yam 8 (spinning) has been interrupted due to a yam 8 break.

Each workstation is further provided with a handling mechanism 16, which is provided with a yam 8 catcher 16a and which is adapted to move the yam catcher 16a between a parking position P1 outside the working space of the workstation and a catching position Z in the suction nozzle 11 . The yam 8 catcher 16a is adapted to catch the yam 8 in the suction nozzle 11 after finding the end of the yam 8 on the bobbin 24 and after sucking the end of the yam 8 into the suction nozzle 11 . The yam 8 catcher 16a is adapted to handle the yam 8 by means of the handling mechanism 16 between the winding device 10 and the spinning device 20, especially for introducing the caught yam 8 from the bobbin 24 to the outlet 200 of the yam 8 from the spinning device 20, for introducing the yam 8 to the yam break sensor 12, for guiding the yam 8 to the yam draw-off mechanism 13 and for guiding the yam 8 to the yam quality sensor 14.

The workstation is further provided with a yam cutting device 1_, which is arranged at the workstation displaceably between its rest position K in Fig. 1 and its cutting position S in Fig. 1 a. In its rest position K, the cutting device 1_ is situated at a distance from the outlet 200 of the yam 8 from the spinning device 20. In its cutting position S, the cutting device 1_ is situated at the outlet 200 of the yam 8 from the spinning device 20.

In the exemplary embodiment shown, the cutting device 1_ is coupled to a drive 15 for displacement between its rest position K and its cutting position S. In the exemplary embodiment shown, the drive 15 of the cutting device comprises a rotary stepper motor and a linear transmission 23, e.g., in the form of a gear wheel and a toothed rack or in the form of a toothed belt, etc. The drive 15 of the motion of the cutting device 1_ between the rest and cutting positions K, S is coupled to a control unit 22, e.g., here the control unit of the workstation. The cutting device 1_ comprises a pair of cutting knives 5, 6 and is coupled to a mechanical accumulator 7 of mechanical cutting energy. The cutting knives 5, 6 are provided with cutting edges 50, 60 oriented against each other, which are adapted to cut the yam 8. The cutting device further comprises a blocker 3 of the mechanical energy accumulated in the mechanical accumulator ?, wherein the blocker 3 is coupled to a mechanical trigger 30 adapted to unblock the blocker 3 and to start cutting the yarn 8. The cutting device is further assigned to a force generator 4 adapted to act on the mechanical accumulator 7 which is adapted to initialize and carry out the accumulation of mechanical cutting energy into the mechanical accumulator 7, ideally during the motion of the cutting device from the cutting position S to the rest position K, as will be described in more detail in the following text.

In the exemplary embodiment shown, the cutting device comprises a fixed knife_5, to which is assigned a cutting knife 6, which is swingable between its open position, see Fig. 2, and its closed position, see Fig. 4, and is mounted in the structure of the cutting device 1_. The open position of the cutting knife 6 in this embodiment of the invention corresponds to the open position of the cutting device before cutting the yarn 8. The closed position of the cutting knife 6 in this embodiment of the invention at the same time corresponds to the closed position of the cutting device after cutting the yarn 8. The swinging cutting knife 6 is at one end 61 coupled to a tension, push, torsion, leaf, etc., spring 70 which in this embodiment forms a mechanical accumulator ?. The swinging cutting knife 6 is at its other end 62 further coupled to a latch 300 which here constitutes the blocker 3 of the mechanical cutting energy accumulated in the mechanical accumulator 7. The latch 300 is mounted at one end 310 of a two-armed lever 31 which is at its other end 311 provided with an eccentric mechanical trigger 30 adapted to unblock the blocker 3 and to start cutting the yarn 8. The eccentric mechanical trigger 30 is adapted to contact the trigger surface of the workstation at the moment when it is necessary to trigger the cutting of the yarn 8, as will also be described below. In the illustrated exemplary embodiment, the trigger surface of the workstation is formed by the surface 201 of the spinning device 20 or another surface of the workstation. In the exemplary embodiment shown, the force generator 4 is provided with a mechanical stop 40, which is arranged in the workstation structure, preferably in the region of the rest position K of the cutting device 1_, to which the cutting device 1_ returns from the spinning device 20 after the operations described below have been performed at the spinning device 1_. The mechanical stop 40 is situated in the path of the cutting device 1. against the contact surface 63 which is arranged on the swinging cutting knife 6, which, during the returning of the cutting device 1_ into its rest position K, is in its closed position, see Fig. 4. The mechanical stop 40 is in the path of the cutting device 1. against the contact surface 63 and in connection with the motion of the cutting device 1. to its rest position K located in such a way that the mechanical stop 40 moves the swinging cutting knife 6 from its closed position to its open position, in which the swinging cutting knife 6 is subsequently automatically locked by the latch 300, e.g., by the action of an unillustrated spring on the blocker 3, and at the same time the spring 70 is tensioned to a state for performing the yam cutting.

The cutting device 1_ is provided with a proximity sensor 9 of the cutting device approaching a selected part of the workstation, e.g., to the spinning device 20, wherein the proximity sensor 9 is coupled to a control unit 22. In another exemplary embodiment, the proximity sensor 9 is replaced with a sensor of the motion of at least one of the knives 5, 6, to detect the moment of unblocking the blocker 3, etc. If the drive 15 of the motion of the cutting device 1. between the rest and cutting positions K, S is implemented by a stepper motor, it is possible to use the sensing of the input power of this motor or the sensing of the magnitude of the electric current of this motor as an alternative to the proximity sensor 9 and/or the sensor of the motion of the knife 5, 6, e.g., using the electronic circuit TMC5160 from Trinamic (www.trinamic.com), technical documentation TMC5160/TMC5160A DATA SHEET (Rev. 1.13/ 2019-NOV-19) page 87 and others. In another exemplary embodiment, the proximity sensor 9 is formed by a mechanical switch or a microswitch.

The method according to the invention is based on the fact that after a yam 8 break, whether due to an error in the production of the yarn or due to insufficient quality of the yarn 8, the handling mechanism 16, thanks to its drive 18, starts to move the yam 8 catcher 16a from its parking position P to the catching position Z, where the rear slot T of the suction nozzle 11 is closed. Subsequently, the vacuum source to the suction nozzle 11 is opened and the suction nozzle 11 approaches the package of the yarn 8 on the bobbin 24, namely at a search distance, and the bobbin 24 starts to rotate in reverse, i.e. , against the direction of rotation during the winding of the yam 8 on the bobbin 24 during the production of the yarn 8. The broken or otherwise loose end of the yarn 8 is sucked into the suction nozzle 11 , where the yam 8 is caught by the catcher 16a. Subsequently, the handling mechanism 16 returns to the initial position with the catcher 16a and the caught yam 8 to the parking position. P. During this motion, the yam 8 is guided to a yam quality sensor 14, to the yam draw-off mechanism 13, to the yam presence/break sensor 12 and to the outlet 200 of the yam 8 from the spinning device 20. Subsequently, the cutting device 1_, the cutting knives 5, 6 of which are opened and the mechanical accumulator 7 of mechanical cutting energy has the accumulated mechanical energy to cut the yam 8 and is locked by the blocker 3, moves from its rest position K to its cutting position S, driving the open cutting knives 5, 6 on the yam 8 to guide it closer to the outlet 200 of the spinning device 20 such that the yam 8 passes between the knives 5, 6. At the moment when the cutting device is sufficiently close to the spinning device 20, ideally at a distance X, the blocker 3 is unblocked, thereby releasing the energy accumulated in the mechanical accumulator 7 and the cutting knives 5, 6 cut the yam 8 passing between them. This approach is detected either by the proximity sensor 9, which transmits a signal to the control unit 22 of the workstation, which stops further motion of the cutting device 1. or it is detected by mechanical contact between a component of the cutting device and the spinning device 20.

In an unillustrated exemplary embodiment, the proximity sensor 9 is replaced with a motion sensor of at least one of the knives 5, 6, thereby detecting the moment of unblocking the blocker 3, etc., or the moment of unblocking the blocker_3, i.e., the start of the motion of the knives 5 and/or 6, is detected from changes in power or in electric current drive 15, etc.

After cutting the yam 8, the automatic operation of the workstation continues, because cutting the yam 8 at the spinning device 20 at the outlet 200 of the yam from the spinning device 20 resulted in forming the end of the yam 8 for introduction to the spinning device and the subsequent preparation of the spinning-in end of the yam to resume spinning. During the backward motion of the cutting device 1_ to the rest position K, at least one of the cutting knives 5, 6 runs on the generator 4 of the tension force acting on the mechanical accumulator 7, resulting in the re-accumulation of mechanical energy for the next cutting of the yam 8 into the mechanical accumulator 7 and locking the mechanical accumulator 7 by the blocker 3, so that the cutting device 1_ is ready for further cutting of the yarn 8 with the accumulated mechanical energy.

In the exemplary embodiment shown in Figs. 2 to 4, the yam cutting device 1 8 operates in such a manner that the cutting device 1. is in its rest position K, the movable knife 6 is rotated to the open position, the spring 70 is extended and the rotation of the movable knife 6 is locked in this position by the latch 300. After finding the end of the yam 8 on the bobbin 24 and guiding the yam 8 by the yam handling mechanism 16 with a yam 8 catcher to the outlet 200 of the spinning device 20, the cutting device 1_ starts to move from its rest position K to its cutting position S at the spinning device 20. In doing so, the yam 8 gets between the open knives 5, 6 and is guided by these knives 5, 6 closer to the outlet 200 of the spinning device 1_. As soon as the cutting device 1. gets close enough to the spinning device 20, the trigger 30 lands on the surface 201 of the spinning device 20, the two-armed lever 31 rotates and the locking of the movable knife 6 by the latch 300 is released, so that the movable knife 6 rotates by pulling the spring 70 and cuts the yam 8 between the knives 5, 6. Subsequently, the cutting device 1. returns do to its rest position K, the lever of the movable knife 6 comes into contact with the mechanical stop 40 of the tensioner 4, the movable knife 6 is rotated to the open position, the spring 70 is again extended and the latch 300 locks the movable knife 6 in this position. This prepares the entire device ready for the next cycle.

Industrial applicability

The invention can be used in rotor or air-jet spinning machines for producing yam which are equipped with unit automation devices to resume the yam production, to perform spinning-in. List of references

I yarn cutting device

10 yarn winding device

100 bobbin holder

I I suction nozzle

12 yarn presence sensor

13 yarn draw-off mechanism

14 yarn quality sensor

15 drive of the cutting device

16 handling mechanism

16a yarn catcher

18 drive of the handling device

20 spinning device

200 yarn outlet

201 surface of the spinning device

21 drafting device

210 sliver

22 control unit

23 linear transmission

24 bobbin

3 blocker of accumulated mechanical cutting energy

30 mechanical trigger of the blocker

300 latch

31 two-armed lever

310 one end of the two-armed lever

311 the other end of the two-armed lever

4 force generator adapted to act on the mechanical accumulator

40 mechanical stop

5 cutting knife

50 cutting edge

6 cutting knife

60 cutting edge

61 one end of the cutting knife

62 the other end of the cutting knife

63 contact surface of the cutting knife 7 mechanical accumulator

70 spring

8 yarn

9 proximity sensor

K rest position of the cutting device of the yam

P direction of motion of the sliver

P1 parking position of the yarn catcher

S cutting position of the cutting device of the yam

T rear slot of the suction nozzle

X proximity distance of the cutting device to the spinning device

Z pick-up position of the yam catcher

Claims

Patent claims

1. A method of cutting off an end part of yarn (8) before resuming the spinning process on a textile machine for producing yam (8), in which, after the spinning process has been interrupted, the yarn (8) is first guided to an outlet (200) of yarn (8) from a spinning device (20) and subsequently, the yarn (8) is interrupted by a cutting device (1 ) to form the end of the yarn (8) to be introduced into the spinning device (20) to resume spinning, whereupon the formed end of the yam (8) is introduced into the spinning device (20) for resuming spinning, characterized in that before interrupting the yam (8) to form the end of the yam (8) for introduction into the spinning device (20), mechanical energy necessary for interrupting the yam (8) is accumulated in the cutting device (1 ) and this accumulated mechanical energy is released in one single step to interrupt the yam (8), thereby providing energy to drive the cutting device (1 ) for forming the end of the yam (8) to be introduced into the spinning device (20).

2. The method according to claim 1 , characterized in that the mechanical energy is accumulated in the cutting device (1 ) during the motion of the cutting device (1 ) between its rest position (K) and cutting position (S).

3. The method according to claim 1 or 2, characterized in that the release of the mechanical energy for interrupting the yam (8) is activated by mechanical contact between the cutting device (1 ) and the surface of the spinning device (20).

4. The method according to claim 1 or 2, characterized in that the release of the mechanical energy for interrupting the yam (8) is activated by a control unit after the cutting device (1 ) has approached the surface of the spinning device (20).

5. The method according to claim 2, characterized in that the mechanical energy is accumulated in the cutting device (1 ) during the linear reciprocating motion of the cutting device (1 ) and this accumulation is performed by mechanical contact of the cutting device (1 ) and a force generator (4).

6. A device for cutting off an end part of yarn (8) before resuming the spinning process on a textile machine for producing yam (8), which comprises a cutting device (1 ), which is adjustable between its rest position (K) and cutting position (S), wherein the cutting device (1 ) is provided with a mechanism for interrupting the yarn (8), the mechanism for interrupting the yarn (8) being connected to a source of its motion for interrupting the yarn (8), characterized in that the source of its motion of the mechanism for interrupting the yarn (8) by the cutting device (1 ) comprises at least one mechanical accumulator (7) of mechanical energy, wherein the mechanism for interrupting the yam (8) by the cutting device (1 ) comprises at least one cutting knife (5,6) and further comprises a generator (4) of force acting on the mechanical accumulator (7), wherein the cutting knife (5, 6) is coupled to the mechanical accumulator (7) of mechanical energy and is further coupled to a blocker (3) of the accumulated mechanical cutting energy, wherein the blocker (3) is coupled to a control element for onetime releasing the accumulated mechanical cutting energy of the cutting device (1 ).

7. The device according to claim 0, characterized in that the mechanical accumulator (7) of mechanical energy comprises at least one spring (70).

8. The device according to claim 0 or 7, characterized in that the cutting device (1 ) comprises at least one proximity sensor (9) of the cutting device (1 ) approach to the spinning device (20), which is coupled to a control unit for releasing the accumulated mechanical cutting energy, and/or the cutting device (1 ) comprises a mechanical contact between the cutting device (1 ) and the surface of the spinning device (20) for releasing the accumulated mechanical cutting energy.

9. The device according to claim 8, characterized in that the proximity sensor (9) is a mechanical switch or microswitch or a sensor of electric current or the performance of the drive (15) of the motion of the cutting device (1 ) between its rest position (K) and cutting position (S).

10. A textile machine for producing yam (8), which comprises a plurality of workstations arranged next to each other in at least one row, wherein each workstation comprises unit automation devices for resuming the production of the yam (8) and also comprises a cutting device (1 ) of the yam (8) for forming the end of the yam (8) to be introduced into a spinning device (20), characterized in that the cutting device (1 ) of the yam (8) is formed according to any of claims 6