DESC:F O R M 2
THE PATENTS ACT, 1970
(39 of 1970)
The Patent Rule, 2003

COMPLETE SPECIFICATION
(See section 10 and rule 13)

AN AUTOMATIC YARN PIECING UNIT FOR A RING SPINNING MACHINE

Lakshmi Machine Works Limited
AN INDIAN COMPANY WHOSE ADDRESS IS PERIANAICKENPALAYAM, COIMBATORE – 641020,
TAMILNADU, INDIA

The following specification particularly describes the invention and the manner in which it is to be performed
FIELD OF THE INVENTION
The present invention relates to textile ring spinning machines. Particularly, the invention relates to an automatic yarn piecing arrangement for textile ring spinning machines. More particularly, the invention deals with an actuating mechanism for the modules in automatic piecing unit of textile ring spinning machines.

BACKGROUND OF THE INVENTION
In textile industries, the textile spinning machines are used to convert the cotton into yarn through a series of machines. It has been observed that yarn breakage in ring spinning machines is a frequent problem which requires continuous attention of the machine operators. The broken yarns have to be pieced manually and the yarn spinning sequence has to be restarted then and thereafter yarn breakage in order to avoid wastage of yarn.
In order to overcome the disadvantages, automatic piecing assemblies were developed as an improvement towards the conventional method of manual piecing. Said automatic piecing assembly involves a robot or worker in a piecing vehicle which has in-built drive units, sensing units, support units which are normally required for automatic piecing arrangements. Such automatic piecing assemblies are functionally required to be moved up and down as well as to be advanced towards the ring spinning machine for piecing operation and then returned back after completion of the piecing operation.
US Patent publication US4028869 discloses a spinning machine with a plurality of spinning stations equipped with automatic or semi-automatic spool-changing mechanisms. The machine has a servicing device, designed for travel along the machine and for repairing thread breakages at some particular spinning location. The presence of this servicing device or carriage at a spinning location would interfere with the operation of the spool-changing mechanism. A controller delivers signals to an appropriate receiver in the servicing device and causes it to depart to a neutral zone at the end of the machine.
It has been observed that existing piecing arrangements are not successful as the yarn lifting module, yarn insertion module and yarn suction modules are unable to reach their working destination automatically and precisely with respect to the yarn winding bobbin as well as vertically moving ring rail. This is because, those modules are moved vertically up and down by corresponding pneumatic actuators with respect to the up and down movement of the ring rail. During working, the piston rod of said pneumatic actuators extends from home to extended position and vice-versa to complete the cycle. But in ring spinning machines, the yarn breakage occurs at any point when the ring rail moves up/down with respect to yarn winding bobbin. Hence for piecing operation, positioning the said yarn lifting module, yarn insertion module and yarn suction modules requires plurality of mechanical stoppers for stopping the corresponding pneumatic actuators at required working destination and height. Since this is a tedious process, the attempts made for moving the yarn suction assembly and yarn inserting assembly relative to the ring rail were not found to be successful.
Moreover, it has also been observed that the usage of pneumatic actuators and stoppers lead to a complicated and bulky construction which increases the cost of automatic piecing arrangements in ring spinning machines. Furthermore, if any failure occurs in functioning of these stoppers, it will lead to accidental damage to moving assemblies and modules of piecing unit. This is an undesirable effect and needs more attention for periodic maintenance of the automatic piecing unit.
Therefore, the object of the present invention is to solve one or more of the aforesaid issue.
OBJECTS OF THE INVENTION
The primary object of the present invention is to provide an automatic piecing unit for piecing broken yarns in a ring spinning machine. The automatic piecing unit comprises an improved actuator assembly for operating the various modules of a yarn piecing unit of textile ring spinning machines.
Another object of the present invention is to provide an actuator assembly having a precise position control to the yarn lifting module, yarn insertion module and yarn suction modules.

SUMMARY OF THE INVENTION
This summary is provided to introduce embodiments related to present invention, and the embodiments are further described below in the detailed description. This summary is not intended to determine or limit the scope of the claimed subject matter.
The present invention provides an automatic yarn piecing unit for piecing broken yarns in a ring spinning machine. The automatic yarn piecing unit comprising: a vertical frame; a first housing having a yarn lifting module and a yarn insertion module mounted at the vertical frame, the yarn lifting module lifts the broken yarn from a cop; the yarn insertion module is positioned above the yarn lifting module to insert the yarn into a traveller of the ring spinning machine; a second housing having a top suction module mounted at the vertical frame for holding the lifted yarn, the top suction module is positioned above the yarn insertion module. The automatic yarn piecing unit further comprises a control unit, a first electro-mechanical actuator unit connected with the control unit configured to operate the vertical movement of the yarn lifting module and the yarn insertion module; and a second electro-mechanical actuator unit connected with the control unit configured to operate the vertical movement of the top suction module. The automatic yarn piecing unit comprises a piecing module mounted at the top portion of the vertical frame, the piecing module performs the piecing operation.
In accordance with the present invention, the first electro-mechanical actuator unit is connected with the first housing whereas the second electro-mechanical actuator unit is connected with the second housing. The first electro-mechanical actuator unit and the second electro-mechanical actuator unit are synchronized with respect to the vertical movement and speed of the ring rail of the ring spinning machine. The electro-mechanical actuator unit comprises a screw rod / belt drive arrangement and drive means.

In accordance with a non-limiting embodiment of the present invention, the drive means of the electro-mechanical actuator unit include any one of a servo motor/stepper motor / BLDC motor, to provide vertical movement to the yarn lifting module, the yarn insertion module and the top suction module.

In accordance with the present invention, the operating position and/or current status of ring rail and its drive is monitored by the control unit which controls the drive of said electro-mechanical actuators units. The position of the ring rail is monitored separately by contact/non-contact type sensors adapted at the automatic yarn piecing unit and the feedback is provided to the control unit. Further, the position of the ring rail is monitored by contact / non-contact type sensors/motor drives adapted at the ring spinning machine and the feedback is provided to the control unit.

In accordance with the present invention, the yarn lifting module comprises an air blow assembly for lifting the broken yarn for piecing operation. The yarn insertion module comprises yarn gripper arms assembly for inserting the yarn into the rotatable traveller of the ring spinning machine. The top suction module comprises a suction mouth for holding the lifted yarn and a lappet tilting assembly.

In accordance with the present invention, the automatic yarn piecing unit comprises a guide rail that allows the automatic piecing unit to move along the longitudinal axis of the ring rail of the ring spinning machine.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Reference will be made to embodiments of the invention which may be illustrated in the accompanying figure(s). These figure(s) are intended to be illustrative and not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
Figure 1 illustrates the automatic piecing unit for a ring spinning machine in accordance with an embodiment of the present application.
Figure 2 illustrates an isometric view of the automatic piecing unit for a ring spinning machine in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
It is to be understood that the singular forms "a,""an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.
In accordance with an embodiment of the present invention, Figures 1 & 2 shows a ring spinning machine (2) provided with an automatic yarn piecing unit (1). The automatic piecing unit (1) comprises a yarn lifting module (3); a yarn insertion module (4) and a top yarn suction module (5). The yarn lifting module (3) and yarn insertion module (4) are placed in a first housing movable up and down in a vertical frame (15) through suitable mounting and sliding means. The yarn lifting module (3) comprises air blowing means (not shown) to lift the broken yarn end upwards from cop (9) after yarn breakage. The yarn insertion module (4) comprises yarn gripping and rocking arms (not shown) to insert the lifted yarn held by suction mouth (6) inside the rotatable traveller of the ring secured in the ring rail (10). The yarn insertion module (4) is positioned above the yarn lifting module (3) in the housing.
The top suction module (5) is provided for holding the lifted yarn received from said yarn lifting module (3) until piecing with the delivery yarn (16) from drafting zone. The top suction module (5) is placed in second housing movable up and down in the vertical frame (15) through suitable mounting and sliding means, at the top portion of vertical frame (15), i.e. above the yarn insertion module (4). A suction mouth assembly (6) is provided in said top suction module (5), said suction mouth assembly (6) comprises a suction mouth and lappet tilting arrangement (7).
The automatic yarn piecing unit comprises a piecing module (14) for piecing the broken yarn held in suction mouth (6) with the fibre/yarn delivering from the drafting zone. The piecing module (14) is mounted at the top portion of vertical frame (15) and is positioned above the top suction module (5).
During yarn breakage, for initiating the piecing operation, the automatic piecing unit (1) with yarn lifting module (3), yarn insertion module (4) and top suction module (5) reaches the yarn winding zone (8) of the yarn spinning machine where the spun yarn is wound on the yarn cop (9) of the ring spinning machine (2) and broken yarn end is entangled in the cop (9). Since the yarn spinning operation is progressing in other winding zones (i.e. 1600 spindles) of the spinning machine, the ring rail (10) continues to move up and down without stopping for the particular yarn breakat a single spindle station / winding zone (8). At this stage, the yarn lifting module (3), yarn insertion module (4) and top suction module (5) have to reach the said winding zone (8) precisely to process the broken yarn.
As per the invention, initially the yarn lifting module (3) and yarn insertion module (4) are precisely positioned and moved synchronously with respect to the moving ring rail (10). To insert the broken yarn into the traveller of the ring spinning machine, the gripping arms in the yarn insertion module (4) moves laterally towards the ring rail (10) which moves up and down along with corresponding ring-traveller, the ring rail (10) is driven commonly for entire length of spinning machine.
In accordance with an embodiment of the present invention, the vertical movement of the housing with yarn lifting module (3) and yarn insertion module (4) is executed by a first electro-mechanical actuator unit (11). Moreover said yarn insertion module (4) co-operatively moves with the ring rail (10) in a synchronized manner until completion of the yarn inserting operation. For inserting broken yarn into the traveller, the arms provided in the yarn inserting module (4) moves laterally towards the ring rail (10). The said lateral movements are executed by suitable actuating means like pneumatic/hydraulic/electrical actuators.The precise position of the said yarn insertion module (4) has to be maintainedin the vertical frame (15) in a synchronized manner without any interruption. To achieve the precise position of the yarn lifting module (3) and the yarn insertion module (4) placed in the first housing in the vertical frame (15), a first electro-mechanical actuator unit (11) is provided to move said yarn lifting module (3) and yarn insertion module (4) synchronously in up/down direction as shown by the arrow. The first electro-mechanical actuator unit (11) is connected with the first housing having yarn lifting module (3) and the yarn insertion module (4) through suitable connecting and mounting means. The electro-mechanical actuator comprises electric motor which drives the in-built screw rod through belt/pulley which provides precise vertical movement and position control to the housing with yarn insertion module (4) and yarn lifting module(3). The first electro-mechanical actuator unit (11) is further connected with the control unit. The electro-mechanical actuator unit (11) is configured to operate the vertical movement of the yarn lifting module (3) and the yarn insertion module (4) at required positions.
The automatic piecing unit (1) further comprises a second electro-mechanical actuator unit (12) connected with the housing of the top suction module (5). The second electro-mechanical actuator unit (12) is further connected with the control unit and is configured to operate the vertical movement of the top suction module (5) precisely.
The position of the broken yarn spindle is identified by the automatic piecing unit (1) based on the input signal received from the sensors adapted in the ring spinning machine (2).
In accordance with a non limiting embodiment of the present invention, said electro-mechanical actuator units (11, 12) comprises a screw rod / belt drive arrangement and drive means. The drive means may be but not limited to a servo motor/stepper motor / BLDC motor which functions so as to achieve a precise movement to the driven modules (3, 4, 5).
According to an embodiment of the present invention, a drive motor or servo drive of the ring rail (10) and the electro-mechanical actuator units (11, 12) are controlled through a central processing unit or control unit. The operating position and/or current status of ring rail(10) and its drive is monitored by the control unit which controls the drive and position of said electro-mechanical actuator units (11, 12). The position of the ring rail (10) is monitored separately by contact/non-contact type sensors provided in the automatic yarn piecing unit (1) and the feedback is provided to the control unit.
In accordance with another embodiment of the present invention, the position of ring rail (10) can also be monitored separately and the feedback received by contact/non-contact type sensors/motor drives adapted at the ring spinning machine (2) is provided to the control unit. Thus the corresponding electro-mechanical actuator units (11, 12) are synchronized with the movement and speed of the ring rail (10). And therefore the up/down movement of yarn lifting module (3), yarn insertion module (4) and yarn suction module (5) is synchronized to moving ring rail (10). Thereafter the air blow assembly of yarn lifting module (3) reaches near yarn winding cop (9) to lift the broken yarn end from said cop(9). Meanwhile the top suction module (5) also reaches the position above the cop (9) of the winding zone (8) to pick the lifted broken end.
The present invention provides a precise position of the said modules driven by the electro-mechanical actuator units (11, 12) in a synchronized manner with respect to vertically moving ring rail (10).
In accordance with another embodiment of the present invention, the second electro-mechanical actuator unit (12) is provided to move the said top suction module (5) up and down in the vertical frame(15). The operating position and/or current status of ring rail (10)and its drive is monitored by the control unit which controls the drive of said electro-mechanical actuator unit(12). The position of the ring rail (10) is monitored separately by contact/non-contact type sensors provided in the automatic yarn piecing unit (1) and the feedback is provided to the control unit.Alternatively, the position of ring rail (10) can also be monitored separately and the feedback is sent to said control unit through contact/non-contact type sensors/motor drives adapted at the ring spinning machine (2).
In accordance with the present invention, the corresponding electro-mechanical actuator unit (11, 12) is synchronized with respect to the movement and speed of the ring rail (10). Thus the top suction module (5) along with suction mouth assembly (6) and lappet tilting assembly (7) comes down to the position of winding zone (8) of the ring spinning machine (2) and consequently lifts the lappet (13) for accessing the top portion of winding cop (9). Thereafter, the yarn suction module (5) is synchronized with respect to moving ring rail (10) as shown by the arrow. Now the broken yarn end is carried by the suction mouth assembly (6) due to the negative pressure created at the suction mouth (6). Now the top suction module (5) moves upward to a predetermined height adjacent to the drafting zone by the retracting action of thesecond electro-mechanical actuator unit (12).This makes the yarn to unravel further from the cop (9) till the top suction module (5) reaches the piecing position or home position.
The yarn gripper arms of yarn insertion module (4) execute the function of inserting the yarn into the ring traveller of the ring spinning machine (2). Then the piecing operation is carried out by the piecing module (14) provided at the top of the vertical frame (15). Since there are at least two electro-mechanical actuator units (11, 12) used for yarn lifting module (3), yarn insertion module (4) and top suction module (5) according to the present invention, a precise position control is achieved in synchronization with the moving ring rail(10). Thereby the need for mechanical stoppers to position/control the automatic piecing unit (1) modules (3, 4, 5) are eliminated.
Figure 2 illustrates the isometric view of the automatic yarn piecing unit (1) for a ring spinning machine (2) in accordance with the present invention. The automatic yarn piecing unit (1) comprises a vertical frame (15); a yarn lifting module (3) adapted inside the first housing slideably mounted at the vertical frame (15) for lifting the broken yarn. The automatic yarn piecing unit (1) comprises a yarn insertion module (4) adapted inside the first housing which is slideably mounted at the vertical frame (15). The yarn insertion module (4) is positioned above the yarn lifting module (3) to insert the yarn into a traveller of the ring spinning machine (2). The automatic yarn piecing unit (1) comprises a top suction module (5) mounted at the vertical frame (15) for holding the lifted yarn. The automatic yarn piecing unit (1) further comprises a control unit; a first electro-mechanical actuator unit (11) connected with the control unit configured to operate the vertical movement of the yarn lifting module (3) and the yarn insertion module (4) at required precise positions; a second electro-mechanical actuator unit (12) connected with the control unit and the top suction module (5), the control unit is configured to operate the vertical movement of the top suction module (5) at required height. The top suction module (5) is having a suction mouth assembly (6).
The automatic yarn piecing unit (1) includes a guide rail (17) connected with the bottom side of the vertical frame (15). The automatic yarn piecing unit (1) moves longitudinally in front of ring spinning machine (2) over the guide rail (17) provided at the base platform. The yarn (16) delivering from drafting zone (drafting rollers are not shown) is wound over the spindle in the form of cop (9).
In accordance with the present invention, during yarn breakage, the yarn lifting module (3) comprising air blowing means lifts the broken yarn end upwards from cop (9), to allow the top suction module (5) to hold the broken yarn end until piecing with the delivery yarn (16) from drafting zone. The yarn insertion module (4) comprises gripping and rocking arms to insert the held yarn end inside the rotatable traveller of the ring secured in the ring rail (10).The precise position of automatic piecing unit (1) and above said modules have to be maintained with the ring rail (10) of ring frame (2) in a synchronized manner without any interruption till the completion of piecing cycle. To achieve a precise position control for the piecing operation, the first electro-mechanical actuator unit (11) is provided for the yarn lifting module (3) and yarn insertion module (4) to move synchronously in up/down direction. The second electro-mechanical actuator unit (12) is provided for the top suction module (5) to move synchronously in up/down direction. The automatic yarn piecing unit comprises a second housing having a top suction module (5) mounted at the vertical frame (15) for holding the lifted yarn.

ADVANTAGES
The present invention has the following advantages:
1. The present device is having electro-mechanical actuator units which provide a precise vertical movement of the yarn lifting module, yarn insertion module and the top suction module.
2. The present invention provides a precise control over the movement of the yarn lifting module, yarn insertion module and the top suction module to perform the piecing operation.
3. The present device provides an effective means to control the movement of the various modules via. Electro-mechanical actuators and thus eliminates need for mechanical stoppers to position/control various yarn handling modules.
4. The present device provides an improved automatic piecing unit which effectively finds, lifts and piece the broken yarn in a ring spinning machine.
5. The present device increases the efficiency of the ring spinning machine by controlling the piecing operation in a precise and effective manner and further, it saves a lot of time in resuming the spinning operation.

The foregoing description of the invention has been set merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the substance of the invention may occur to person skilled in the art, the invention should be construed to include everything within the scope of the disclosure.
,CLAIMS:We Claim:
1. An automatic yarn piecing unit(1) for piecing broken yarns in a ring spinning machine (2), the automatic yarn piecing unit(1) comprising:
a vertical frame(15);
a first housing having a yarn lifting module(3) and a yarn insertion module (4) mounted at the vertical frame (15), the yarn lifting module (3) lifts the broken yarn from a cop(9);
the yarn insertion module(4) positioned above the yarn lifting module (3) to insert the yarn into a traveller of the ring spinning machine(2);
a second housing having a top suction module(5) mounted at the vertical frame(15) for holding the lifted yarn, the top suction module (5) is positioned above the yarn insertion module(4);
a control unit;
a first electro-mechanical actuator unit(11) connected with the control unit configured to operate the vertical movement of the yarn lifting module (3) and the yarn insertion module(4);
a second electro-mechanical actuator unit(12) connected with the control unit configured to operate the vertical movement of the top suction module(5); and
a piecing module(14) mounted at the top portion of the vertical frame (15), the piecing module (14) performs the piecing operation.
2. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the first electro-mechanical actuator unit (11) is connected with the first housing.

3. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the second electro-mechanical actuator unit (12) is connected with the second housing.

4. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the first electro-mechanical actuator unit (11) and the second electro-mechanical actuator unit (12) are synchronized with respect to the vertical movement and speed of the ring rail (10) of the ring spinning machine (2).

5. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the electro-mechanical actuator unit (11, 12) comprises a screw rod / belt drive arrangement and drive means.

6. The automatic yarn piecing unit (1) as claimed in claim 5, wherein the drive means include any one of a servo motor/stepper motor / BLDC motor, to provide vertical movement to the yarn lifting module(3), the yarn insertion module(4) and the top suction module (5).

7. The automatic yarn piecing unit (1) as claimed in claim 4, wherein the operating position and/or current status of ring rail (10) and its drive is monitored by the control unit which controls the drive of said electro-mechanical actuator units (11, 12).

8. The automatic yarn piecing unit (1) as claimed in claim 4, wherein the position of the ring rail (10) is monitored separately by contact/non-contact type sensors adapted at the automatic yarn piecing unit(1) and the feedback is provided to the control unit.

9. The automatic yarn piecing unit (1) as claimed in claim 4, wherein the position of the ring rail (10) is monitored by contact / non-contact type sensors/ motor drivesadapted at the ring spinning machine (2) and the feedback is provided to the control unit.

10. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the yarn lifting module (3) comprises an air blow assembly for lifting the broken yarn for piecing operation.

11. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the yarn insertion module (4) comprises yarn gripper arms assembly for inserting the yarn into the rotatable traveller of the ring spinning machine (2).

12. The automatic yarn piecing unit(1) as claimed in claim 1, wherein the top suction module (5) comprises a suction mouth(6) for holding the lifted yarn and a lappet tilting assembly (7).

13. The automatic yarn piecing unit (1) as claimed in claim 1, wherein the automatic yarn piecing unit (1) comprises a guide rail (17) that allows the automatic piecing unit(1) to move along the longitudinal axis of the ring rail (10) of the ring spinning machine(2).

Dated this 22nd day of January. 2021

For Lakshmi Machine Works Limited
By their Agent

(D. Manoj Kumar) (IN/PA 2110)
KRISHNA & SAURASTRI ASSOCIATES LLP