Field of the Invention

The present invention relates to a suction device for suction and transport of yarn for a service robot for a yarn manufacturing textile machine, especially a ring spinning machine.

The invention also relates to a service robot for performing service operations at a spinning station of a textile machine, especially a ring spinning machine, comprising at least one suction device for suction and transport of yarn.

In addition, the invention also relates to a yarn manufacturing textile machine, espe cially a ring spinning machine, comprising at least one service robot.

Background of the Invention

In yarn production, suction of the yarn by suction air into a suction nozzle is used to catch and handle the yarn. The suction air is generated either by connecting a vacu um source to the suction nozzle, or by using an ejector connected to a compressed air source which, by passing through the ejector, generates a suction vacuum at the suction mouth of the ejector.

Such suction devices are known, for example, from DE2326485A1 , JP2001341939A, JPS57102469A, US4236374A and US4667864A.

The disadvantages of the suction devices used so far include their structural and manufacturing complexity, energy intensity as well as their weight causing dynamic loading of the positioning mechanisms of the robot and also of the textile machine.

Principle of the invention

The aim of the invention is to eliminate or at least reduce at least one of the draw backs of the background art by ensure reliable transport of the yarn through the suc tion device, reduce yarn tension and maintain the twist of the yarn. The aim of the invention is achieved by a suction device for suction and transport of yarn for a service robot of a yarn manufacturing textile machine, especially a ring spinning machine, whose principle consists in that a suction mouth is fluidically con nected to an inner conduit by means of a suction conduit and a first vacuum ejector is arranged in the area associated with a rear opening and is adapted to create a pres sure gradient between the suction mouth and the rear opening to transport the air flow through the suction mouth via the suction conduit to the inner conduit, whereby at least one yarn twist retaining element is disposed in the inner conduit between the suction device and the first vacuum ejector.

A suction device according to the present invention typically comprises a suction tube that is provided with a front opening and a rear opening, whereby the front opening is fluidically connected to the rear opening by an inner conduit (e.g. an inner channel). The suction device further comprises a suction mouth, which is arranged at the front opening, and a first vacuum ejector, which is fluidically connected to the inner con duit. The suction mouth is fluidically connected to the inner conduit by means of a suction conduit (e.g. an inner channel) The first vacuum ejector is arranged in the area associated with the rear opening (i.e. is arranged at the region adjacent to the downstream opening) and is adapted to generate (when in an operating state) a pressure gradient between the suction mouth and the rear opening for conveying an air flow through the suction mouth via the suction conduit to the inner conduit (hence drawing an air stream through the suction mouth via the suction channel into the in ner conduit. At least one yarn twist retaining element is arranged in the inner conduit between the suction mouth and the first vacuum ejector.

Such a device not only guarantees a reliable suction of the yarn into the suction tube, but also ensures reliable transport of the yarn through the suction tube, yarn tension and maintaining the twist and all this while maintaining low weight, common energy sources, low dynamic loading of the positioning device, etc.

In order to make sure that the yarn is sucked into the suction tube, it is advantageous if the first vacuum ejector is adapted such that when generating a pressure gradient between the suction mouth and the rear opening when the air flow is conveyed through the suction mouth via the suction conduit to the inner conduit, the air flow has a first average velocity in the cross-section of the suction conduit and in the cross section of the inner conduit it has a second average velocity, the first average velocity being greater than the second average velocity.

According to a preferred embodiment, at least a part of the suction conduit has a smaller cross-section than the cross-section of the inner conduit associated with the first vacuum ejector.

In addition, it is advantageous if the suction conduit and the inner conduit have both a circular cross-section, the inner diameter of the suction conduit being smaller than the inner diameter of the inner conduit associated with the first vacuum ejector.

In order to improve the suction of the yarn into the front end of the suction tube, it is advantageous if the suction mouth is fluidically connected to a suction inlet (a further suction mouth) of a second vacuum ejector arranged between the suction mouth and the front opening of the suction tube, the first and the second vacuum ejector being connected to the same source of compressed air. In this example, to achieve differ ent velocities of the sucked air, it is sufficient for the suction mouth of the front ejector to have a correspondingly smaller cross-section than that of the suction mouth of the rear ejector.

According to another embodiment, the suction mouth of the suction tube is fluidically connected to a suction inlet (a further suction mouth) of a second vacuum ejector arranged between the suction mouth and the front opening of the suction tube, whereby each of the vacuum ejectors is connected to a different source of com pressed air, so that to achieve different velocities of the sucked air, it is sufficient to use correspondingly different compressed air for each of the ejectors, optionally also in combination with different cross-sections of the suction conduit of the front ejector and of the suction mouth of the rear ejector.

From the manufacturing as well as functional point of view, it is advantageous if the yarn twist retaining element is formed by a curved section of the suction tube. To improve the retention of the yarn twist, the curved section is provided with at least one yarn twist retaining device. The yarn twist retaining device preferably has a con tact surface to obtain physical contact with a yarn arranged in the suction conduit in order to prevent untwisting of the yarn.

According to another preferred embodiment, the yarn twist retaining element is formed by at least one yarn twist retaining device arranged in a straight section of the suction tube, as subsequently will be explained in more detail.

According to yet another preferred embodiment, the yarn twist retaining element is formed by a curved trajectory of the suction tube which comprises at least three bends of the suction tube.

Generally, it is important for the operator of the textile machine to form the yarn end or to shorten the sucked yarn into individual sections, and it is therefore advanta geous if a yarn cutting device is arranged in the suction tube before the first vacuum ejector, hence upstream of the first vacuum ejector.

According to a preferred embodiment, the yarn cutting device is coupled to an air drive piston, which is advantageous in view of the possible connection of this drive to the same compressed air distribution system which is used to create suction in the suction tube, thereby saving considerable resources and reducing the weight of the device, the load on the drive mechanisms, dynamic effects, etc.

The present invention is also directed to a service robot for performing service opera tions at a spinning station of a textile machine, preferably of a ring spinning machine that comprises at least one suction device for the suction and transport of yarn as described herein.

The principle of a service robot for performing service operations at a spinning station of a textile machine, preferably a ring spinning machine, consists in the fact that it comprises at least one suction device for the suction and transport of the yarn ac cording to any of the preceding paragraphs, or according to any of claims 1 to 12. Above all, the advantage of this embodiment is saving considerable means for the operation of the functional nodes of a service robot involved in the suction and han dling of the yarn, the reduction of the weight of the yarn suction and handling means, the reduction of the load on the drive mechanisms and drives of a service robot, the reduction of the dynamic effects on the other parts of a service robot and, finally but importantly, the reduction of the requirements for the energy performance of a ser vice robot, preferably by using one common distribution system of compressed air for several functions with different airflow rates, etc.

The present invention is also directed to a textile machine for producing of yarn, pref erably a ring spinning machine, comprising at least one service robot as described herein.

The principle of a yarn manufacturing textile machine, especially a ring spinning ma chine, comprising at least one service robot, consists in that the service robot is de signed according to claim 13.

Such a yarn manufacturing textile machine, especially a ring spinning machine, is then automatically operable, with low and acceptable load on the existing machine working groups, with low additional energy requirements and high efficiency of yarn suction and yarn handling.

Brief Description of Drawings

The herein described invention will be more fully understood from the detailed de scription of the given herein below and the accompanying drawings, which should not be considered as limiting to the invention described in the appended claims. The in vention is schematically shown in the drawings, wherein

Fig. 1 shows an exemplary embodiment of a device for the suction and transport of the yarn according to the invention;

Fig. 1 a shows an exemplary embodiment of the device for the suction and transport of the yarn with yarn twist retaining devices inserted in the straight front part of the suction tube; Fig. 1 b shows an exemplary embodiment of the device for the suction and transport of the yarn with a yarn twist retaining device inserted in the curvature in the rear part of the suction tube;

Fig. 2 shows an alternative exemplary embodiment of the device for the suc tion and transport of the yarn according to the invention with a pair of vacuum ejectors;

Fig. 3 shows an alternative arrangement of the curvature in the rear part of the suction tube;

Fig. 4 is a longitudinal sectional view of the front end of the suction tube ac cording to the embodiment of the device of Fig. 1 ; and

Fig. 4a is a longitudinal sectional view of the front end of the suction tube with the second vacuum ejector according to the embodiment of the device of Fig. 2.

Detailed Description of the Invention

The invention will be described with reference to an exemplary embodiment of a de vice for the suction and transport of the yarn 1 arranged on a service robot of a yarn manufacturing textile machine, especially a ring spinning machine. A yarn manufac turing textile machine, i.e., also a ring spinning machine, comprises at least one row of identical spinning stations (not shown) arranged next to each other. Each spinning station comprises unillustrated nodes and devices for producing yarn 1 and for wind ing yarn on an unillustrated bobbin.

The textile machine further comprises at least one service robot, which is reversibly movable along the row of spinning stations and is provided with a system of nodes and devices for performing service operations and activities at the spinning station.

One of these robot nodes and devices for performing service operations and activi ties at the spinning station is a handling means 2 for spatial manipulation with the yarn 1 , which is spatially adjustably arranged on the robot frame. One of the exam- pies of a specific embodiment of such a handling means 2 for spatial manipulation with the yarn 1 is, for example, the solution according to the Czech patent application No. 2018-48.

The device for the suction and transport of the yarn 1 is arranged on the handling means 2 for spatial manipulation with the yarn 1 , or, more specifically, it is arranged on the end motion element of the handling means 2. This device allows the sucked yarn 1 to be manipulated by the handling means 2 for spatial manipulation with the yarn 1 or by the end motion element the handling means 2 for spatial manipulation with the yarn 1 with the required degrees of freedom and within the required area of the robot action range for performing the necessary service operations and activities at the spinning station within the required range of the spinning station.

The device for the suction and transport of yarn 1 comprises a suction tube 0. The suction tube 0 is provided with a front opening 02 and a rear opening 01 , whereby the front opening 02 is by an inner conduit 03 of the suction tube 0 fluidically connected to the rear opening 01 of the suction tube 0. The suction tube 0 is provided at its front end with a suction mouth 00 with a longitudinal suction conduit 000, which, through the front opening 02 of the suction tube 0, opens into the inner conduit 03 of the suc tion tube 0. In the embodiment of Figures 1 , 1a and 4, the suction mouth 00 is ar ranged at the front end of the suction tube 0 as a fitted end piece. In an unillustrated exemplary embodiment, the suction mouth 00 with the suction conduit 000 is formed, e.g., by narrowing the front end of the suction tube 0, etc. The suction conduit 000 has preferably a circular cross-section and has a diameter di on at least a part of its length. The inner conduit 03 of the suction tube 0 has preferably a circular cross- section and has a diameter d ₂ on at least a part of its length.

The suction tube 0 is on its rear part, or at its rear end, provided with a first vacuum ejector 3 whose suction inlet 30 is fluidically connected to the inner conduit 03 of the suction tube 0. The first vacuum ejector 3 is by its compressed air intake 31 connect ed to a source of compressed air 5, which may e.g. be a high pressure air system with pressure tank and compressed air hoses. Due to this compressed air, the first vacuum ejector 3 generates a pressure gradient between the suction mouth 00 and the rear opening 01 of the suction tube 0 for conveying an air flow through the suction mouth 00 via the suction conduit 000 to the inner conduit 03 of the suction tube 0, i.e. for sucking the air through the suction mouth 00 via the suction conduit 000 to the inner conduit 03 of the suction tube 0 and then for blowing the air flow through the rear opening 01 out of the inner conduit 03 of the suction tube 0. Thus, the first vacu um ejector 3 sucks in the air from the inner conduit 03 of the suction tube 0 through it suction inlet 30 and blows it out through the rear opening 01 at the rear end of the suction tube 0.

When creating the pressure gradient between the suction mouth 00 and the rear opening 01 of the suction tube 0, the first vacuum ejector 3 sucks the air into the suc tion tube 0 through the suction mouth 00 via the suction conduit 000, in which this air flow has a first velocity Vi in the cross-section, whereas in the cross-section of the inner conduit 03, the air flow has a second average velocity v _2. The velocities Vi and v ₂ depend on the size of the cross-section of the suction conduit 000 and that of the inner conduit 03 as well as on the suction effect of the first vacuum ejector 3, i.e. on the pressure gradient between the suction mouth 00 and the rear opening 01.

In order to ensure reliable suction of the yarn 1 into the suction conduit 000 of the suction mouth 00, sufficient air suction before the suction mouth 00 of the suction tube 0 is necessary, or before the suction conduit 000 of the suction mouth 00, whereby for the transport of the yarn 1 through the inner conduit 03 of the suction tube 0, the required suction effect is not as high as before the suction conduit 000. Therefore, the suction conduit 000 of the suction mouth 00 according to the embodi ment of Figs. 1 , 1a and 4 has a smaller cross-section, or has a smaller diameter d-i, than the size of the cross-section, or the diameter d ₂ , of the inner conduit 03 of the suction tube 0. Consequently, also the first average velocity v-i of the air flowing (sucked in) through the suction conduit 000 from the space before the suction mouth 00 is greater than the second average velocity v ₂ of the air flowing (sucked in) into the inner conduit 03 of the suction tube 0.

In the embodiment of Figs. 2 and 4a, the suction tube 0 is at its front end provided with a second vacuum ejector 4, which is advantageous when the suction or the pressure gradient created by the first vacuum ejector 3 (the embodiment according to Figs. 1 , 1a and 4) does not achieve the required pressure gradient between the suc tion mouth 00 and the rear opening 01 and the required suction effect before the suc tion mouth 00. The suction mouth 00 is fluidically connected to a suction inlet 40 of a second vacuum ejector 4 arranged between the suction mouth 00 and the front open ing 02 of the suction tube 0, whereby the suction mouth 00 is either disposed at the front end of the second vacuum ejector 4, or the suction inlet 40 of the second vacu um ejector 4 directly forms the suction mouth 00. The suction inlet 40 of the second vacuum ejector 4 is arranged on the front side of a body 41 of the second vacuum ejector 4, whereby in the rear side of the body 41 of the second vacuum ejector 4, the front end of the suction tube 0 is mounted, as shown in detail in Fig. 4a. The second vacuum ejector 4, which is connected to the source of compressed air 5, sucks the air through the suction mouth 00 to the inner conduit 03 of the suction tube 0, i.e. creates a pressure gradient at the first average velocity Vi depending on the cross- sectional size or the diameter di of the suction conduit 000, the suction of the second vacuum ejector 4 being supported by the first vacuum ejector 3. In the illustrated ex emplary embodiment, the first and the second vacuum ejectors 3, 4 are connected to the same source of compressed air 5.

In an unillustrated exemplary embodiment of the solution with a pair of vacuum ejec tors 3 and 4, the first and second vacuum ejectors 3 and 4 are connected to different sources of compressed air, in terms of the size of the pressure of the compressed air.

Between the suction mouth 00 and the first vacuum ejector 3, or between the first and second vacuum ejectors 3 and 4 in the embodiment with two vacuum ejectors 3, 4, the suction tube 0 is in its inner conduit 03 provided with at least one yarn twist retaining element 9 to retain the twist of the yarn 1 in the inner conduit 03 of the suc tion tube 0.

In the exemplary embodiment of Fig. 1 , the yarn twist retaining element 9 is formed by an end curved section 91 of the suction tube 0, wherein the end curved section 91 is, for example, formed by a circular curvature having radius R ₄ . In the exemplary embodiment of Fig. 1 b, at least one yarn twist retaining device 90 is arranged in the end curved section 91 in the inner conduit 03 of the suction tube 0. The yarn twist retaining device 90 has a contact surface adapted to contact the yarn 1 .

Fig. 3 shows an alternative embodiment of the rear part of the suction tube 0 with the first vacuum ejector 3, wherein the suction tube 0 before the first vacuum ejector 3 comprises an upstream and a downstream straight section 10 and 1 1 , between which is arranged the curved section 91 of the suction tube 0, in which at least one yarn twist retaining device 90 is mounted in the inner conduit 03 at the top of the curved section 91 , whereby the first vacuum ejector 3 is associated with the downstream straight section 1 1 of the suction tube 0 and due to its connection to the source 5 of compressed air it sucks in the air into the suction tube 0 at a velocity v ₂ from the front part of the suction tube 0 (not shown here) with the suction conduit 000.

Before the curved section 91 of the suction tube 0, the yarn cutting device 7 is ar ranged in the suction tube 0, such as scissors, a chopper, etc., connected to a drive, e.g., to an air drive piston 71 , which is through the intake 72 controllably connected to the source of compressed air, e.g., to a common source of compressed air 5. In the embodiment of Fig. 3, the yarn cutting device 7 is arranged in the upstream straight section 10 of the suction tube 0.

In the area before the yarn cutting device 7, the suction tube 0 in the embodiment of Fig. 1 is straight, has a smooth inner surface, i.e. without yarn 1 twist retaining ele ments.

In the embodiment in Fig. 1a, the suction tube 0 is straight in the area before (up stream of) the yarn cutting device 7 and at least one yarn twist retaining device 90 is disposed in its inner conduit 03.

In the embodiment of Fig. 2, the suction tube 0 is in the area before (upstream of) the yarn cutting device 7 provided with a Curved trajectory X1 , which, for example, com prises a trio of mutually counter circular bends 6 having radii R-i, R ₂ and R ₃ and which reaches an offset value H. In an unillustrated exemplary embodiment, the end part of the suction tube 0 is straight and at least one yarn twist retaining device 90 is dis posed therein.

The invention is not limited to the embodiments expressly described or illustrated herein, but may also be implemented in other specific embodiments, particularly in the light of the combination of the individual variants described above to create an other specific embodiment of the device.

The present invention is applicable to the textile industry in the production of yarn and in textile machinery in the production of machines and service robots.

Reference Numerals

1 Yarn 71 Air drive piston

0 Suction tube 72 Intake

00 Suction mouth 20 9 Yarn twist retaining element 01 Rear opening (of the suction 90 Yarn twist retaining device tube) 91 Curved section (of the suction

02 Front opening (of the suction tube)

tube) 10 First straight section

03 Inner conduit 25 11 Second straight section 000 Suction conduit v-i First average velocity

2 Handling means v ₂ Second average velocity

3 First vacuum ejector di Inner diameter of the suction

4 Second vacuum ejector conduit

40 Suction inlet 30 d ₂ Inner diameter of the inner 5 Source of compressed air conduit

6 Bend X1 Curved trajectory

7 Yarn cutting device