AN AUTOMATIC YARN PIECING APPARATUS AND A METHOD THEREOF

Abstract

 The present invention relates to an automatic yarn piecing apparatus (9) of a textile ring spinning machine (1) and a method of piecing the broken yarns to drafted fibre strands. The yarn piecing apparatus (9) comprises a lifting unit for lifting the broken yarn from the cop (8), a suction unit (10) adapted to accommodate the broken yarn lifted by the lifting unit, and a piecing unit (11) configured to join a tail end (15) of the broken yarn to a fibre strand drafted by a drafting unit (4). The piecing unit (11) comprises a positioning device (12) adapted to perform an over-piecing process to merge the tail end (15) of the broken yarn to the fibre strand.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to textile spinning machines. Particularly, the invention relates to an automatic yarn piecing apparatus for piecing broken yarn ends in ring spinning machines, compact yarn spinning machines etc. More particularly, the invention deals with handling as well as piecing of broken yarns in an automatic yarn piecing unit of textile ring spinning machines, and a method for piecing the broken yarns in the ring spinning machines.

BACKGROUND OF THE INVENTION

[0002] The subject matter discussed in the background section should not be assumed to be prior art merely because of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may correspond to implementations of the claimed technology.

[0003] In textile spinning mills, ring spinning machines are used to produce yarn from fibres which are drafted and twisted and then wound on a cylindrical shell, known as cop or bobbin. During such conventional spinning processes, yarn breakage in the ring spinning machines is a common and frequent problem that requires continuous attention of the workforce. The yarn breakage nowadays remains a major disadvantage in ring spinning machines which has forced huge number of workforce to continuously monitor the ring spinning machines throughout length of the machine frame. The broken yarns have to be pieced manually and the yarn spinning sequence has to be restarted then and there after yarn breakage in order to avoid wastage of yarn.

[0004] With the advent of the modern technology, automatic piecing devices are provided as an improvement towards the conventional techniques of manual piecing of fibres. Such automatic piecing devices involve a robot or worker in a piecing vehicle or piecing device which has inbuilt drive units and supportive functional units, movable along the length of the ring spinning machine frame. At a particular broken yarn spindle station, such automatic piecing devices are required to advance towards the ring spinning machines for piecing operation and return to their original position after completion of the piecing operation.

[0005] Such known piecing arrangements practically fail to properly piece the broken yarn owing to various parameters such as yarn count, machine speed and humidity playing a major role while binding the broken yarn with delivery fibres during the piecing operation. Moreover, the failure of a particular piecing cycle is consequently carried on to further attempts for piecing the yarn repeatedly until completion of a successful piecing operation. This contributes in creation of a lot of yarn waste if there are many such occurrences throughout the machine length during a production period in a spinning mill.

[0006] The present invention has been envisaged in view of the above-mentioned circumstances, and it is an object thereof to provide a novel and improved piecing arrangement for an automatic yarn piecing apparatus of textile ring spinning machines, compact spinning machines etc.

OBJECTS OF THE INVENTION

[0007] An object of the present invention is to provide an automatic yarn piecing apparatus capable of effectively piecing yarn to delivery fibre strands in ring spinning machines, and a method thereof.

[0008] Another object of the present invention is to provide an automatic yarn piecing apparatus capable of reducing yarn wastage, and a method thereof.

[0009] Another object of the present invention is to provide a reliable and efficient automatic yarn piecing apparatus capable of performing improved and accurate piecing of broken yarn ends, and a method thereof.

SUMMARY OF THE INVENTION

[0010] In order to achieve the above-mentioned objects, according to an aspect of the present invention, an automatic yarn piecing apparatus for a ring spinning machine is disclosed. The automatic yarn piecing apparatus includes a lifting unit for lifting a broken yarn from cop of the ring spinning machine, a suction unit for accommodating the broken yarn lifted by the lifting unit, and a piecing unit for joining a tail end of the broken yarn to fibre strand drafted by a drafting unit of the ring spinning machine. The piecing unit includes a positioning device for performing an over-piecing process to merge the tail end of the broken yarn to the fibre strand. The positioning device is provided with a yarn joining device configured to move in horizontal and traverse directions with respect to the drafting unit to perform over-piecing.

[0011] According to an embodiment of the present invention, the suction unit includes a tubular mouth for accommodating the tail end of the broken yarn before a drafting roller pair of the drafting unit. The tail end of the broken yarn may be accommodated in the tubular mouth by applying a negative pressure through the tubular mouth.

[0012] According to an embodiment of the present invention, the piecing unit includes the yarn joining device configured to move in horizontal and traverse directions with respect to the drafting unit, by a set of first and second actuators, and a set of stoppers for limiting excess movement of the yarn joining device. The actuators are pneumatic or hydraulic or screw rod type.

[0013] According to an embodiment of the present invention, the yarn joining device is hinged at a fulcrum point, and includes a nose portion adapted to move the tail end of the broken yarn accommodated by the tubular mouth to a position in between the front rollers and the middle rollers suitable for the over-piecing process.

[0014] According to an embodiment of the present invention, the yarn joining device along with carried tail yarn is moved left side of front top roller, moved towards top drafting rollers and moved in right direction to perform over-piecing for yarn breakage at left side drafting rollers. Further, the yarn joining device along with carried tail yarn is moved right side of front top roller, moved towards top drafting rollers and moved in left direction to perform over-piecing for yarn breakage at right side drafting rollers.

[0015] According to an embodiment of the present invention, the piecing unit includes a cutter assembly mounted in proximity of the yarn joining device. The cutter assembly performs a cutting operation for excess length of the broken yarn. The cutter assembly includes a fixed blade member, a movable blade member, and a cutter assembly actuator. The movable blade member performs a scissor action around a fulcrum joint with respect to the fixed blade member to cut the excess length of the broken yarn.

[0016] According to an embodiment of the present invention, the automatic yarn piecing apparatus further includes a spindle brake actuating mechanism configured to apply brake to a spindle station during piecing operation of the broken yarn.

[0017] Another aspect of the present invention pertains to an automatic yarn piecing method for a ring spinning machine capable of effectively piecing yarn to delivery fibre strands in ring spinning machines, while reducing yarn wastage and performing improved and accurate piecing of broken yarn ends. The method involves lifting a broken yarn from a cop of the ring spinning machine, accommodating the broken yarn lifted by the lifting unit, and joining a tail end of the broken yarn to a fibre strand drafted by a drafting unit of the ring spinning machine.

[0018] According to an embodiment of the present invention, the automatic yarn piecing method also includes performing an over-piecing process to merge the tail end of the broken yarn to the fibre strand, by moving a yarn joining device in horizontal and traverse directions with respect to the drafting unit.

[0019] According to an embodiment of the present invention, the automatic yarn piecing method also involves the steps of generating a negative pressure through the tubular mouth of the suction unit to enable the tubular mouth to accommodate the tail end of the broken yarn before the drafting roller pair of the drafting unit.

[0020] According to an embodiment of the present invention, the yarn joining device is moved in horizontal and traverse directions with respect to the drafting unit, by a set of first and second actuators, and excess movement of the yarn joining device is limited by a set of stoppers. A nose portion of the yarn joining device moves the tail end of the broken yarn accommodated by the tubular mouth to a position in between the front rollers and the middle rollers suitable for the over-piecing process.

[0021] According to an embodiment of the present invention, the yarn joining device along with carried tail yarn is moved left side of front top roller, moved towards top drafting rollers and moved in right direction to perform over-piecing for yarn breakage at left side drafting rollers. Further, the yarn joining device along with carried tail yarn is moved right side of front top roller, moved towards top drafting rollers and moved in left direction to perform over-piecing for yarn breakage at right side drafting rollers.

[0022] According to an embodiment of the present invention, the automatic yarn piecing method further includes the steps of cutting an excess length of the broken yarn after piecing.

[0023] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

[0024] 

Fig. 1 illustrates a schematic representation of a two-sided ring frame machine wherein only one spinning station is shown for illustrative purpose.

Fig. 2 illustrates a schematic representation of a spinning station and an automatic yarn piecing apparatus in a ring spinning machine, in accordance with an embodiment of the present invention.

Fig. 3 illustrates a schematic representation of the automatic piecing apparatus with a piecing arm assembly in retracted position and a tail end of broken yarn held in a suction unit during piecing sequence, in accordance with an embodiment of the present invention.

Fig. 4 illustrates a schematic representation of the automatic yarn piecing apparatus with the piecing arm assembly in extended position i.e., in front of a drafting unit, during the piecing sequence, in accordance with an embodiment of the present invention.

Figs. 5 and 6 illustrate schematic representations of the piecing arm assembly and a positioning device of the automatic yarn piecing apparatus, in accordance with an embodiment of the present invention.

Figs. 7 and 8 illustrate schematic representations of the positioning device and a cutter assembly of the automatic yarn piecing apparatus, in accordance with an embodiment of the present invention.

Fig. 9 illustrates a schematic representation of the automatic yarn piecing apparatus with the piecing arm assembly in retracted position after completion of the piecing operation, in accordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0025] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the present invention and is not intended to represent the only embodiments in which the present invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention, and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

[0026] It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the preferred, arrangements and methods are now described.

[0027] Exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. This disclosure may however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those of ordinary skill in the art. Moreover, all statements herein reciting embodiments of the disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure).

[0028] Referring to Fig. 1, the ring spinning machine (1) comprises at least a spinning station (2) where a supplied roving or unspun thread i.e. fibre federation (3) passes downwards to a drafting unit (4), equipped with a plurality of top and bottom drafting rollers (5a, 5b, 6a, 6b, 7a, 7b). A weighting arm presses three top rollers (5a, 6a, 7a) on to the three bottom rollers (5b, 6b, 7b), which rotate at different speeds. The back rollers (7a, 7b) rotate at a slow speed, while the intermediate pair of rollers (6a, 6b) rotates faster than the first pair of rollers. The front rollers (5a, 5b) rotate at a very high speed. Because of these different speeds and the loads on the top rollers, the supplied roving (3), which is fed into the drafting unit (4), is drawn, and is considerably reduced in thickness.

[0029] While leaving the last pair of top and bottom rollers of the drafting unit (4), the roving is given a twist by a ring with a rotating traveller and a rotating spindle, which are located underneath the drafting unit (4) system. The twist creates friction between the fibres by which the strength of the fibre mass increases. In this state, the fibre mass is now called yarn. The yarn is wound on to a bobbin attached to the spindle. The yarn is delivered through delivery rollers nip (5a, 5b) and then wound on a bobbin attached to the spindle to form a yarn cop (8).

[0030] As illustrated in Fig. 2, when there is a yarn breakage, the automatic yarn piecing apparatus (9) comes in front of the spinning station (2). The automatic yarn piecing apparatus (9) includes a lifting unit for lifting the broken yarn from the cop (8), at least an insertion unit for inserting the yarn into a traveler, a top suction unit (10) for holding the lifted yarn, and a piecing unit (11) for joining the broken yarn end to the drafted fibres in the drafting unit (4). A suction is created and by a tubular mouth (16) provided in the suction unit (10), yarn is lifted from the cop (8) and held in the mouth (16). The yarn piecing unit (11) further comprises a yarn positioning device (12) and a support frame (13) for providing support to the yarn positioning device (12). Further, an advancing mechanism (not shown in figure) is provided for moving the said support frame towards and away from the drafting unit (4). At this stage, a broken yarn end (15') of the fibre strand is continuously carried by the suction force of a broken end collection tube (14) of the spinning station (2), whereas a tail yarn (15) goes along with the cop (8).

[0031] Fig. 3 of the present invention illustrates the manner in which the broken portion of the tail yarn from the cop is held in the tubular mouth portion. When the automatic yarn piecing apparatus (9) moves towards the spinning station (2) in case of yarn breakage, a spindle brake actuating mechanism (not shown in figure) of the piecing apparatus (9) applies brake to the running spindle of the rotating cop (8). A negative pressure i.e., a suction is applied though the tubular mouth (16) provided in the top suction unit (10) of the piecing apparatus (9). Therefore, a suction force is created and the tail yarn (15) from the cop (8) is carried to the open end of the mouth (16). Thus, carried tail yarn (15) is held in tubular mouth (16) itself for a predetermined period during piecing action. Meanwhile, the piecing arm assembly (17) is held in home position.

[0032] According to an embodiment of the present invention, the suction unit of (10) the automatic piecing apparatus (9) may include a single venturi jet or two venturi jets instead of large suction motors, for picking the yarn end from the cop (8). The venturi jet may receive compressed air and blows air upstream of the cop (8). The venturi jet may have a plurality of tapered inlets through which air is blown inside, thereby creating suction force inside the suction unit (10) in upward direction to lift the broken yarn end from the cop. Thus, the compressed air leaving the venturi jet at the outlet creates suction force in upward direction which in turn picks the yarn end from the cop (8). In another embodiment, in addition to the venturi jet, plurality of air jets may be provided to assist in lifting the broken yarn end from the cop (8).

[0033] As shown in Fig. 4, the piecing arm assembly (17) moves from its home position to its working position i.e., towards the drafting unit (4), hence the tail yarn (15) held by tubular mouth (16) is also carried forward up to the drafting unit (4). The tail yarn (15) is brought up to front drafting roller pair (5a, 5b) of the drafting unit (4). Now, the yarn positioning device (12) provided in piecing arm assembly (17) executes an over-piecing process to merge the tail yarn (15) with the drafting fibre strand between the drafting roller pairs (5a, 5b, 6a, 6b) and to complete the piecing action. Meanwhile, the spindle brake is released to resume the yarn winding operation onto the cop (8). According to the invention, the term "over piecing" refers to a method of inserting the broken yarn into the drafting zone in which the fibres are being drafted and thereby merging the said broken yarn end to the drafting fibres itself. Thus, the broken yarn end and drafting fibre joins together. Said yarn positioning device (12) is operated by a set of pneumatic/electrical or screw rod actuators. The actuators facilitate the movement of the said yarn positioning device in x-y-z directions, according to the requirement.

[0034] An isometric view of the piecing arm assembly (17) according to the present invention is shown in Figs. 5 to 7 of the drawings. The piecing arm assembly (17) as shown comprises a piecing arm lever (18) which is provided with a yarn positioning device (12), wherein a yarn joining device (19) is provided for handling the yarn received from the tubular mouth (16) of the top suction unit (10). Said yarn joining device (19) is operated horizontally and traversely by using plurality of pneumatic/electrical or screw rod actuators. The horizontal movement of the yarn joining device (19) herein, refers to the movement parallel to the shafts on which the drafting rollers (5a, 5b, 6a, 6b, 7a, 7b) are mounted, wherein the shafts of each pair of rollers are parallel to each other. The top rollers (5a, 5c, 6a, 6c, 7a, 7c) of each pair of roller may be mounted either on same shaft or on different shafts. Hence, the horizontal movement is left to right movement or right to left movement, while traverse movement herein refers to movement in radial direction i.e., towards the roller or away from it. Front end of yarn joining device (19) is provided with a nose (20) for holding the tail yarn and the other end is connected to a second actuator (22), while the center of said yarn joining device (19) is hinged at a fulcrum point (23). A first actuator (21) is used to move the yarn joining device (19) in horizontal direction, which is parallel to drafting rollers shaft (24) and the second actuator (22) is used to move the yarn joining device in traverse or radial direction, which is perpendicular to drafting rollers shaft (24). Since the yarn joining device (19) is hinged at fulcrum point (23), the inclined angle extended position of second actuator (22) makes the yarn joining device (19) to move in traverse or radial direction, which is perpendicular to drafting rollers shaft (24) as mentioned. The lowering of or home position of second actuator (22) makes the yarn joining device (19) to return from drafting roller area.

[0035] In the piecing arm lever (18), the yarn positioning device (12) is mounted in such a way that the yarn joining device (19) can be traversed horizontally and radially with respect to the front drafting roller pair (5a, 5b). The movement of said yarn joining device (19) towards the front drafting roller pair (5a, 5b) is shown in arrows for left side drafting rollers (5a, 6a) in Figure 7 and for right side drafting rollers (5c, 6c) in Figure 8. The excess movement of first pneumatic/electrical or screw rod actuator (21) can be controlled or limited by using a first stopper (21'), wherever required. The movement of the first stopper (21') is controlled by another associated actuator (21"), which is vertically movable as shown in Fig. 5. Similarly the excess movement of second pneumatic/electrical or screw rod actuator (22) is controlled or limited by using another stopper (not shown). A cutter assembly (25) and associated actuator (26) is mounted behind the yarn joining device (19) to carry out the scissor operation for cutting excess length of tail yarn (15) after piecing. Said actuator (26) of yarn cutter assembly (25) is preferably a pneumatic device and/or hydraulic actuator or screw rod actuator.

[0036] During piecing operation as shown in Fig. 7, for left side drafting rollers (5a, 6a), the tail yarn (15) caught by the tubular mouth (16) is held before front drafting roller pair (5a, 5b) of drafting unit (4). Here, drafting roller (5b) is not shown for illustrative purpose. Now the piecing arm lever (18) along with yarn positioning device (12) advances towards the said drafting unit (4) and hence the said tail yarn (15) catches with the nose portion (20) of yarn joining device (19). Since the yarn is positioned in middle face of front roller pairs (5a, 5b), it has to be moved around the front top roller (5a) for executing the over piecing activity. Hence the yarn joining device (19) along with carried tail yarn (15) to be moved left side of front top roller (5a) and this position is achieved by extending first actuator (21) to left direction. Then the second actuator (22) lifts from home position to the retraction position and thus makes yarn joining device (19) along with yarn to move towards top drafting rollers (5a, 6a). It is in such a way that the nose (20) of yarn joining device (19) to reach the middle space between first top drafting roller (5a) and second top drafting roller (6a) . Then the first actuator (21) is retracted to move the joining device (19) in right direction. Therefore the yarn carried by the nose portion (20) of yarn joining device (19) merges with the drafting fibres of drafting rollers and piecing action is carried out as shown by arrows. Meanwhile the spindle brake is released to resume the yarn winding operation onto the cop. Subsequently the cutter assembly (25) provided at the rear side of yarn joining device (19) is actuated by cutter actuator (26) to cut the extra or remaining yarn after piecing. After this piecing operation, the said yarn joining device (19) return back to original or home position by reversing the corresponding first and second actuators (21, 22).

[0037] If yarn break occurs at right side of top drafting rollers set (5c, 6c, 7c), the yarn joining device (19) along with carried tail yarn (15) to be moved right side of front top roller (5c) as shown in Fig. 8 and this position is achieved by retracting first actuator (21) to right direction which is its most retracted position. Then the second actuator (22) lifts from home position to the retraction position and thus makes yarn joining device (19) along with yarn to move towards top drafting rollers (5c, 6c). Now the nose (20) of yarn joining device reaches the middle space between first right side top drafting roller (5c) and second right side top drafting roller (6c). Then the first actuator (21) is extended to move the joining device in left direction. Therefore the yarn carried by the nose portion of yarn joining device merges with the drafting fibres of drafting rollers and piecing action is carried out as shown by arrows. Meanwhile the spindle brake is released to resume the yarn winding operation onto the cop. Then the cutter assembly (25) cuts the extra or remaining yarn after piecing. And thereafter the yarn joining device (19) return back to original or home position by reversing the corresponding first and second actuators (21, 22).

[0038] The cutter assembly (25) which is mounted on the yarn piecing arm assembly (17) comprises a fixed blade member (27), a movable blade member (28) and a cutter assembly actuator (26). The movable blade member (28) closes and opens with respect to the fixed blade member (27) like a scissor action when the cutter assembly actuator (26) extends. Said movable blade member (28) is of having a substantially V-shape wherein one end is connected to cutter assembly actuator (26) by means of a connecting plate. The fulcrum joint (29) is provided to assist the scissor action (shown by arrow) of movable blade member (28) while the cutter assembly actuator (26) extends and retracts.

[0039] Fig. 9 shows the position of yarn piecing apparatus (9) after finishing the piecing operation according to the present invention wherein the tail yarn (15) from the cop (8) is joined together with the drafting fibre strand and the spinning operation continues. Now the piecing arm assembly (17) of the piecing apparatus (9) returned to original position and the apparatus is scheduled for next piecing cycle. Advantageously, the piecing apparatus according to the present invention results in improved and accurate piecing of the broken yarn ends effectively as this method of over piecing is highly reliable and provides higher success rate.

[0040] In view of the present disclosure which describes the present invention, all changes, modifications and variations within the meaning and range of equivalency are considered within the scope and spirit of the invention. It is to be understood that the aspects and embodiment of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiment may be combined together to form a further embodiment of the disclosure.

Claims

1. An automatic yarn piecing apparatus (9) for a ring spinning machine (1) comprising:

a lifting unit configured to lift a broken yarn from a cop (8) of the ring spinning machine (1);

a suction unit (10) adapted to accommodate the broken yarn lifted by the lifting unit; and

a piecing unit (11) configured to join a tail end (15) of the broken yarn to a fibre strand drafted by a drafting unit (4) of the ring spinning machine (1),

wherein the piecing unit (11) comprises a positioning device (12) adapted to perform an over-piecing process to merge the tail end (15) of the broken yarn to the fibre strand, said positioning device (12) is provided with a yarn joining device (19) configured to move in horizontal and traverse directions with respect to the drafting unit (4) to perform over-piecing.

2. The automatic yarn piecing apparatus (9) as claimed in claim 1, wherein
the suction unit (10) comprises a tubular mouth (16) adapted to accommodate the tail end (15) of the broken yarn before a drafting roller pair (5a, 5b) of the drafting unit (4), by applying a negative pressure through the tubular mouth (16).

3. The automatic yarn piecing apparatus (9) as claimed in claim 1, wherein
the yarn joining device (19) is configured to move in horizontal and traverse directions with respect to the drafting unit (4), by a set of first and second actuators (21, 22) which are pneumatic or hydraulic or screw rod type; and a set of stoppers (21', 22") for limiting excess movement of the yarn joining device (19).

4. The automatic yarn piecing apparatus (9) as claimed in claim 2 or claim 3, wherein
the yarn joining device (19) is hinged at a fulcrum point (23), and comprises a nose portion (20) adapted to move the tail end (15) of the broken yarn accommodated by the tubular mouth (16) to a position in between the front rollers (5a, 5c) and the middle rollers (6a, 6c) suitable for the over-piecing process.

5. The automatic yarn piecing apparatus (9) as claimed in claim 4, wherein the yarn joining device (19) along with carried tail yarn (15) is moved left side of front top roller (5a), moved towards top drafting rollers (5a, 6a) and moved in right direction to perform over-piecing for yarn breakage at left side drafting rollers (5a, 6a).

6. The automatic yarn piecing apparatus (9) as claimed in claim 4, wherein the yarn joining device (19) along with carried tail yarn (15) is moved right side of front top roller (5c), moved towards top drafting rollers (5c, 6c) and moved in left direction to perform over-piecing for yarn breakage at right side drafting rollers (5c, 6c).

7. The automatic yarn piecing apparatus (9) as claimed in claim 1, wherein
the piecing unit (11) comprises a cutter assembly (25) mounted in proximity of the yarn joining device (19), and adapted to perform a cutting operation for excess length of the broken yarn, the cutter assembly (25) comprising:

a fixed blade member (27);

a movable blade member (28); and

a cutter assembly actuator (26),

wherein the movable blade member (28) performs a scissor action around a fulcrum joint (29) with respect to the fixed blade member (27) to cut the excess length of the broken yarn.

8. The automatic yarn piecing apparatus (9) as claimed in claim 1, further comprising:

a spindle brake actuating mechanism configured to apply brake to a spindle of the cop (8) during piecing of the broken yarn.

9. An automatic yarn piecing method for a ring spinning machine (1) comprising the steps of:

lifting, by a lifting unit, a broken yarn from a cop (8) of the ring spinning machine (1);

accommodating, by a suction unit (10), the broken yarn lifted by the lifting unit; and

joining, by a piecing unit (11), a tail end (15) of the broken yarn to a fibre strand drafted by a drafting unit (4) of the ring spinning machine (1),

wherein the step of joining the tail end (15) of the broken yarn to the drafted fibre strand comprises performing, by a positioning device (12), an over-piecing process to merge the tail end (15) of the broken yarn to the fibre strand, by moving a yarn joining device (19) in horizontal and traverse directions with respect to the drafting unit (4).

10. The method as claimed in claim 9, wherein the step of accommodating the broken yarn lifted by the lifting unit further comprises:
generating a negative pressure through a tubular mouth (16) of the suction unit (10) to enable the tubular mouth (16) to accommodate the tail end (15) of the broken yarn before a drafting roller pair (5a, 5b) of the drafting unit (4).

11. The method as claimed in claim 9, wherein the yarn joining device (19) is moved in horizontal and traverse directions with respect to the drafting unit (4), by a set of first and second actuators (21, 22); and limiting excess movement of the yarn joining device (12) by a set of stoppers (21', 22").

12. The method as claimed in claim 11, wherein a nose portion (20) of the yarn joining device (19) moves the tail end (15) of the broken yarn accommodated by the tubular mouth (16) to a position in between the front rollers (5a, 5c) and the middle rollers (6a, 6c) suitable for the over-piecing process.

13. The method as claimed in claim 12, wherein the yarn joining device (19) along with carried tail yarn (15) is moved left side of front top roller (5a), moved towards top drafting rollers (5a, 6a) and moved in right direction to perform over-piecing for yarn breakage at left side drafting rollers (5a, 6a).

14. The method as claimed in claim 12, wherein the yarn joining device (19) along with carried tail yarn (15) is moved right side of front top roller (5c), moved towards top drafting rollers (5c, 6c) and moved in left direction to perform over-piecing for yarn breakage at right side drafting rollers (5c, 6c).

15. The method as claimed in claim 9, further comprising the step of:
cutting, by a cutter assembly (25), excess length of the broken yarn after pieci

Drawing