YARN THREADING ARRANGEMENT IN A PIECING UNIT OF RING SPINNING MACHINE

Abstract

 The present invention relates to an automatic piecing unit (2) of a ring spinning machine (10) for piecing broken yarns. The automatic piecing unit (2) comprises a top suction tube (15) for holding an end of a broken yarn (12) inside, a gripper arm (3), a rocker arm (4), a tensioning arm (7) and a blow jet (6). The gripper arm (3) moves to hook the end of the yarn (12) held between the top suction tube (15) and the cop (17). A rocker arm (4) moves to hook the end of the yarn (12) held between the gripper arm (3) and the cop (17). A tensioning arm (7) is configured such that the yarn (12) held does not make contact with the balloon control ring (19) and guides upon the tensioning arm (7) and reaches the traveler (13) position without any hindrance. The gripper arm (3) and the rocker arm (4) holds the yarn (12) tangential to the ring (14) such that the yarn (12) is threaded inside the rotating traveler (13) by the blow jet (6).

Description

FIELD OF THE INVENTION

[0001] The present invention relates to textile spinning machines. Particularly, the invention relates to an automatic piecing unit for piecing broken yarn ends in textile ring spinning machines. More particularly, the invention deals with an improved yarn threading arrangement in a piecing unit for inserting broken yarn end into a ring traveler of textile ring spinning machine.

BACKGROUND OF THE INVENTION

[0002] Ring spinning machines are the resultant yarn producing machines in textile spinning mill industry. Globally, textile spinning mill industry is facing a long pending problem, which is frequent yarn breakage in ring spinning machines. The yarn breakage is a major problem that needs regular attention of the workers. The yarn breakage nowadays remains a major disadvantage in ring spinning machines which has forced huge number of workers to continuously monitor the ring spinning machines at both the sides throughout the length of the machine frame, which is normally more than 1600 spindles and more than 75 meters long. The broken yarns are required to be pieced manually by the workers and the yarn spinning sequence has to be restarted then and there after yarn breakage, in order to avoid wastage of yarn. Nowadays, the availability of manual workers is a huge demand in spinning mill industry and also there is an urgent need for automation in spinning mills. Even though limited number of workforce is available, the physical ability and health of the workers gets affected due to continuous walking along the long ring spinning frames to manually piece the broken yarn ends throughout the day, as the spinning mills are operating round the clock unless there is any maintenance or power shutdown.

[0003] As an improvement towards the conventional method of manual piecing, automatic piecing units are being developed. The automatic piecing devices involves a robot or worker in a piecing vehicle or piecing device which has in-built drive units and sensing units which are normally required for automatic piecing arrangements. Such automatic piecing devices are advanced towards the ring spinning machine for piecing operation and returned back after completing the piecing operation. The existing piecing arrangements were so far not successful since the piecing unit does not have any automatic means for successfully inserting the yarn to be pieced into the ring traveler, which is the main task.

[0004] During cop build up, the balloon control ring of ring spinning machine moves vertically up and down along with the ring rail of ring spinning machine, which hinders the insertion / threading of yarn by the automatic piecing unit into the rotatable traveler of ring spinning machine.

[0005] In US patent 3807155, an automatic piecing unit was disclosed. The said patent teaches a method and apparatus for joining (piecing) yarns, on a ring spinning frame. In this patent, the broken yarn is threaded into traveler by using numerous links and levers mounted on a large lifting plate, over which the said multiple links and levers are mounted. The construction is very complex with multiple number of arms. It uses a stopper arm to stop the running of the traveler by an air jet stream, a guide rod with hooks and guides for leading an unwound yarn, which is unwound from the spool, toward the hook. A guide lever is pivoted on the lifting plate by a pivot pin, so that the unwound yarn held by pulling hook, is led to the traveler by the motion of the guide lever in accordance with the downward motion of the guide rod. Further, a pushing lever with traveler hanger is swingably mounted on the lifting plate and the traveler hanger is swingably mounted on the front end portion of the pushing lever, so that the traveler hanger is capable of swinging in upward and downward directions. The above prior art patent provides a complicated mechanism for yarn joining with complex drives, which is not practically feasible and also not successfully implemented till date due to the technical difficulties involved.

[0006] Our co-pending patent application no. 201841017625 provided an improved solution for inserting broken yarn end inside the rotatable traveler using gripping and rocking arms. The said mechanism inserts yarn inside traveler by looping balloon control ring, ie. the yarn contacting balloon control ring. Also there are some hindrances while mounting yarn break sensor on ring rail if said mechanism is used for yarn insertion, i.e. yarn break sensor could not be mounted on ring rail.

[0007] In order to overcome the above shortcomings, the forthcoming invention disclosure provides a novel and improved yarn threading arrangement in a piecing unit of textile ring spinning machine.

OBJECTS OF THE INVENTION

[0008] The main object of the present invention is to provide an improved automatic piecing unit for textile ring spinning machines.

[0009] Another object of the present invention is to provide a novel and improved yarn threading arrangement for automatic piecing unit of the textile ring spinning machines.

[0010] Yet another object of the present invention is to provide an improved yarn threading arrangement in a piecing unit which inserts yarn inside the rotatable traveler even in the presence of yarn break sensor unit upon the ring rail and also without contacting / looping yarn with balloon control ring which moves vertically up and down along with ring rail of ring spinning machines.

SUMMARY OF THE INVENTION

[0011] According to the invention, a textile ring spinning machine is provided with an improved automatic piecing unit. The automatic piecing unit comprises a top suction tube for holding an end of a broken yarn lifted from a cop of the ring spinning machine. The top suction tube moves upstream near a drafting zone and passes the yarn into a lappet hook of the ring spinning machine. The automatic piecing unit further comprises a gripper arm of a threading arrangement configured to move towards a left position of the cop, move horizontally towards right for hooking the end of the yarn held between the top suction tube and the cop, and move along with the hooked yarn backwards and then downwards to a position below a balloon control ring plane. The gripper arm is provided with a hook type tip for pulling the yarn. The automatic piecing unit further comprises a rocker arm of the threading arrangement configured to move forward. The gripper arm is moved leftward and the rocker arm is moved in backward direction for hooking the end of the yarn held between the gripper arm and the cop. The gripper arm is moved in forward direction towards the cop. When the gripper arm moves in the forward direction towards the cop, a tensioning arm advances towards the yarn. The automatic piecing unit further comprises a blow jet configured to rotate a traveler of the ring spinning machine. The tensioning arm and the blow jet are placed in an adjacent housing.

[0012] In one aspect, the gripper arm and the rocker arm are placed in a housing, and holds the yarn tangential to the ring such that the yarn is threaded inside the rotating traveler by the blow jet. The gripper arm, the rocker arm, and the tensioning arm are retracted to release the yarn from hooks and inserting the yarn inside the traveler.

[0013] In one aspect, the tensioning arm is configured to advance forward such that the yarn held does not make contact with the balloon control ring and guides upon the tensioning arm and reaches the traveler position without any hindrance.

[0014] In one aspect, a yarn break sensor of the ring spinning machine is pointed towards the cop at right position of the spindle and the threading arrangement is advanced at left position of cop, in which condition, the traveler is rotated anticlockwise for yarn threading. Alternatively, the yarn break sensor of the ring spinning machine is pointed towards the cop at left position of the spindle and the threading arrangement is advanced at right position of cop, in which condition, the traveler is rotated clockwise for yarn threading.

[0015] In one aspect, vertical movement of the housing of the tensioning arm is performed by actuating means which includes pneumatic, electric, linear, and hydraulic actuators.

[0016] In one aspect, the tensioning arm is advanced forward through actuating means, which includes pneumatic, electric, linear, and hydraulic actuators.

[0017] In one aspect, the yarn is automatically guided inside the balloon control ring by tension after threading inside the traveler and ready for subsequent piecing with delivery yarn from the drafting zone.

[0018] Present invention also describes a method of piecing broken yarns using an automatic piecing unit of a ring spinning machine. The method comprises lifting an end of a broken yarn from a cop and holding the end of the yarn inside a top suction tube. The method further comprises moving the top suction tube upstream near a drafting zone and passing the yarn into a lappet hook of the ring spinning machine. The method further comprises moving a gripper arm of a threading arrangement placed in the automatic piecing unit towards a left position of the cop. The method further comprises horizontally moving the gripper arm towards right for hooking the end of the yarn held between the top suction tube and the cop. The method further comprises moving the gripper arm along with the hooked yarn backwards and then moving the gripper arm along with the hooked yarn downwards to a position below a balloon control ring plane. The method further comprises moving a rocker arm of the threading arrangement in a forward direction. The method further comprises moving the gripper arm in a horizontal leftward direction and moving the rocker arm backward for hooking the end of the yarn held between the gripper arm and the cop. The method further comprises moving the gripper arm in a forward direction towards the cop for threading the yarn. The method further comprises advancing a tensioning arm in forward direction towards the yarn before threading the yarn inside a traveler. The method further comprises rotating the traveler in an anticlockwise direction using a blow jet. The gripper arm and the rocker arm holds the yarn tangential to the ring such that the yarn is threaded inside the rotating traveler by the blow jet. The method further comprises retracting the gripper arm, the rocker arm, and the tensioning arm to release the yarn from hooks and inserting the yarn inside the traveler.

[0019] In an aspect, the tensioning arm is advanced forward such that the yarn held does not make contact with the balloon control ring and guides upon the tensioning arm and reaches the traveler position without any hindrance.

[0020] In an aspect, the traveler rotates in an anticlockwise direction for yarn threading when the yarn break sensor is placed in a right position of the cop and the threading arrangement is advanced at a left position of the cop. Alternatively, the traveler rotates in a clockwise direction for yarn threading when the yarn break sensor is placed in a left position of the cop and the threading arrangement is advanced at a right position of the cop.

[0021] In an aspect, the rocker arm, the gripper arm, and the tensioning arm move upwards and downwards along with the ring rail in synchronization for hooking the end of the yarn.

[0022] In an aspect, the yarn is guided inside the balloon control ring by tension and becomes available for subsequent piecing with delivery fibre from the drafting zone of the ring spinning machine.

[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] 

Figures 1 and 1a illustrates the isometric view and top view respectively of the yarn threading arrangement of the automatic piecing unit for ring spinning machine according to the present invention.

Figures 2 and 2a illustrates the mounting arrangement of tensioning arm unit housing in automatic piecing unit according to the present invention.

Figure 3 illustrates the side view depicting top suction tube of automatic piecing unit with yarn held inside according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0025] Referring to figures 1 to 3, the yarn threading arrangement (1) of an automatic piecing unit (2) comprises a gripper arm (3) and a rocker arm (4) placed in a common housing (5). Further, a blow jet arm (6) and a tensioning arm (7) are placed in a separate housing (8) movable vertically in synchronization with a ring rail (9) of a ring spinning machine (10), in a linear movement unit adjacent to the gripper arm (3) and the rocker arm (4) housing (5) of the automatic piecing unit (2). The tensioning arm (7) unit housing (8) rests on ring rail (9) of the ring spinning machine (10) through mounting means (11) and moves along up and down together with the ring rail (9) during a yarn threading operation. The controlled movement of said housing (8) is performed by suitable sensors and actuators, preferably of pneumatic type. The actuators can also be one of electric, hydraulic, linear, etc. After threading the yarn (12) end into the traveler (13) of a ring (14), the threading arrangement (1) is retracted and said yarn (12) held in the top suction tube (15) is pieced with delivery yarn from a drafting zone (16) of the ring spinning machine (10).

[0026] Before initiating piecing, the broken yarn spindle is braked, the broken yarn end is lifted from a cop (17) and held inside the top suction tube (15). The top suction tube (15) then moves upstream near the drafting zone (16) of the ring spinning machine (10) such that the yarn (12) is passed into a lappet hook (not shown) of the ring spinning machine (10). The gripper arm (3) of the threading arrangement (1) placed in the automatic piecing unit (2) is moved forward to the left position of the broken yarn spindle / cop (17), whereas a yarn break sensor (18) of ring spinning machine (10) is pointed towards the cop (17) at right position of the spindle. Then, the gripper arm (3) is provided with a horizontal movement towards right, thereby hooking the yarn (12) end which is held between the top suction tube (15) and the cop (17). The gripper arm (3) is provided with a hook type tip for pulling the yarn (12). Then the gripper arm (3) along with the hooked yarn is moved backwards and subsequently moved downwards to a position below a balloon control ring (19) plane.

[0027] Subsequently, the rocker arm (4) of the threading arrangement (1) which is placed in the same housing (5) adjacent to the gripper arm (3) at left side, is moved forward. Then, the gripper arm (3) is provided with a horizontal leftward movement. Afterwards, the rocker arm (4) is provided with a backward movement, thereby hooking the yarn end held between the gripper arm (3) and the cop (17). At this stage, the rocker arm (4) and the gripper arm (3) are moving together along with the ring rail (9) up and down in synchronization.

[0028] Then, the gripper arm (3) is provided with forward movement towards the cop (17) for threading the yarn (12). While the gripper arm (3) is moving forward, the tensioning arm (7) according to the present invention mounted in the adjacent housing (8) in a separate module from that of a gripper unit is advanced towards the yarn (12) held between the gripper arm (3) and the cop (17). Normally, the tensioning arm (7) is in retracted position. Before threading the yarn (12) inside the traveler (13), the tensioning arm (7) is advanced forward through actuating means (20), preferably pneumatic, but also includes any type of actuating means. This advancing of the tensioning arm (7) is such that the yarn held does not make contact with the balloon control ring (19) and guides upon the tensioning arm (7) and reaches the traveler (13) position without any hindrance. If the tensioning arm (7) is not provided, the yarn (12) held in the gripper arm (3) loops inside the balloon control ring (19) and makes it hindrance to thread inside the traveler (13). The tensioning arm (7) movement positively guides the yarn (12) and ensures the yarn (12) is held tangential to the ring (14) for successful threading inside the traveler (13). Subsequently, the traveler (13) is rotated anticlockwise by means of a blow jet (6) placed in the housing of the tensioning arm (7) adjacently. The gripper arm (3) and the rocker arm (4) holds the yarn (12) tangential to the ring (14), at left side such that the yarn is threaded inside the rotating traveler (13) due to the blow jet (6). Subsequently, all the arms, i. e. the gripper arm (3), the rocker arm (4), and the tensioning arm (7) are retracted such that yarn (12) is released from hooks in quick succession and readily inserted inside the traveler (13). The yarn (12) is automatically guided inside the balloon control ring (19) in the path by tension and ready for subsequent piecing with delivery yarn from the drafting zone (16) of the ring spinning machine (10). After piecing, the spindle brake is relieved.

[0029] The horizontal linear and sideway movements of the gripper arm (3), the rocker arm (4), and the tensioning arm (7) and the front and back movements of the threading arrangement (1) are performed by actuating means, which may be electric, pneumatic, rotary, linear, hydraulic etc.

[0030] According to the present invention, the yarn break sensor (18) is placed at right position and the threading arrangement (1) is advanced at left position of the cop (17), in which condition, the traveler (13) is rotated anticlockwise for yarn threading.

[0031] According to another embodiment of the present invention, the yarn break sensor (18) can be placed at left position and the threading arrangement (1) can be advanced at right position of the cop (17), in which condition, the traveler (13) is rotated clockwise for yarn threading.

[0032] Referring to figures 2 and 2a, the tensioning arm (7) unit housing (8) mounting in automatic piecing unit (2) is shown. The tensioning arm (7) and the blow jet arm (6) are mounted in said housing (8). The housing (8) is vertically guided in the linear motion guideway (21) mounted in the automatic piecing unit frame (22) through the actuating means (23) mounted to the frame (22), preferably pneumatic type. The actuating means (23) can also include electric, hydraulic, etc. The tensioning arm (7) unit housing (8) moves in synchronization with the ring rail (9) through the mounting means (11) and suitable sensors, stoppers and actuators. The synchronization with the ring rail (9) can be contact / non-contact type.

[0033] The above described yarn threading arrangement for the automatic piecing unit (2) holds the yarn (12) well in advance in front of the balloon control ring (19) so that the gripper arm (3) and the rocker arm (4) threads the yarn (12) inside the traveler (13) even in the presence of the yarn break sensor (18) upon the ring rail (9) and also without contacting / looping with the balloon control ring (19) which moves vertically up and down along with the ring rail (9) of ring spinning machines. Hence, the automatic piecing operation is very effective and advantageous according to the present invention.

[0034] According to an embodiment of the present invention, the gripper arm, rocker arm, tensioning arm movements can be done in any sequences and any directions for yarn threading operation inside the traveler.

[0035] 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.

Claims

1. An automatic piecing unit (2) of a ring spinning machine (10) for piecing broken yarns, the automatic piecing unit (2) comprising:

a top suction tube (15) for holding an end of a broken yarn (12) lifted from a cop (17) of the ring spinning machine (10), wherein the top suction tube (15) moves upstream near a drafting zone (16) and passes the yarn (12) into a lappet hook of the ring spinning machine (10);

a gripper arm (3) of a threading arrangement (1), provided with a hook type tip for pulling the yarn (12), wherein the gripper arm (3) is configured to:

move towards a left position of the cop (17),

move horizontally towards right for hooking the end of the yarn (12) held between the top suction tube (15) and the cop (17), and

move along with the hooked yarn (12) backwards and then downwards to a position below a balloon control ring (19) plane;

a rocker arm (4) of the threading arrangement (1) configured to move forward, wherein the gripper arm (3) is moved leftward and the rocker arm (4) is moved in backward direction for hooking the end of the yarn (12) held between the gripper arm (3) and the cop (17), and wherein the gripper arm (3) is moved in forward direction towards the cop (17);

wherein when the gripper arm (3) moves in the forward direction towards the cop (17), a tensioning arm (7) advances towards the yarn (12); and

a blow jet (6) configured to rotate a traveler (13) of the ring spinning machine (10), wherein the gripper arm (3) and the rocker arm (4) holds the yarn (12) tangential to the ring (14) such that the yarn (12) is threaded inside the rotating traveler (13) by the blow jet (6),

wherein the gripper arm (3), the rocker arm (4), and the tensioning arm (7) are retracted to release the yarn (12) from hooks and inserting the yarn (12) inside the traveler (13).

2. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein the tensioning arm (7) is configured to advance forward such that the yarn (12) held does not make contact with the balloon control ring (19) and guides upon the tensioning arm (7) and reaches the traveler (13) position without any hindrance.

3. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein a yarn break sensor (18) of the ring spinning machine (10) is pointed towards the cop (17) at right position of the spindle and the threading arrangement (1) is advanced at left position of cop (17), in which condition, the traveler (13) is rotated anticlockwise for yarn threading.

4. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein a yarn break sensor (18) of the ring spinning machine (10) is pointed towards the cop (17) at left position of the spindle and the threading arrangement (1) is advanced at right position of cop (17), in which condition, the traveler (13) is rotated clockwise for yarn threading.

5. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein the gripper arm (3) and rocker arm (4) of the threading arrangement (1) are placed in a housing (5).

6. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein the tensioning arm (7) and the blow jet (6) are placed in an adjacent housing (8).

7. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein vertical movement of the housing (8) of the tensioning arm (7) is performed by actuating means (23) which includes pneumatic, electric, linear, and hydraulic actuators.

8. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein the tensioning arm (7) is advanced forward through actuating means (20), which includes pneumatic, electric, linear, and hydraulic actuators.

9. The automatic piecing unit (2) of the ring spinning machine (10) as claimed in claim 1, wherein the yarn is automatically guided inside the balloon control ring (19) by tension after threading inside the traveler (13) and ready for subsequent piecing with delivery yarn from the drafting zone (16).

10. A method of piecing broken yarns using an automatic piecing unit (2) of a ring spinning machine (10), the method comprising:

lifting an end of a broken yarn (12) from a cop (17) and holding the end of the yarn (12) inside a top suction tube (15);

moving the top suction tube (15) upstream near a drafting zone (16) and passing the yarn (12) into a lappet hook of the ring spinning machine (10);

moving a gripper arm (3) of a threading arrangement (1) placed in the automatic piecing unit (2) towards a left position of the cop (17);

horizontally moving the gripper arm (3) towards right for hooking the end of the yarn (12) held between the top suction tube (15) and the cop (17);

moving the gripper arm (3) along with the hooked yarn backwards and then moving the gripper arm (3) along with the hooked yarn (12) downwards to a position below a balloon control ring (19) plane;

moving a rocker arm (4) of the threading arrangement (1) in a forward direction;

moving the gripper arm (3) in a horizontal leftward direction and moving the rocker arm (4) backward for hooking the end of the yarn (12) held between the gripper arm (3) and the cop (17);

moving the gripper arm (3) in a forward direction towards the cop (17) for threading the yarn (12);

advancing a tensioning arm (7) in forward direction towards the yarn (12) before threading the yarn (12) inside a traveler (13);

rotating the traveler (13) in an anticlockwise direction using a blow jet (6), wherein the Gripper arm (3) and the rocker arm (4) holds the yarn (12) tangential to the ring (14) such that the yarn (12) is threaded inside the rotating traveler (13) by the blow jet (6); and

retracting the gripper arm (3), the rocker arm (4), and the tensioning arm (7) to release the yarn (12) from hooks and inserting the yarn (12) inside the traveler (13).

11. The method as claimed in claim 10, wherein the tensioning arm (7) is advanced forward such that the yarn (12) held does not make contact with the balloon control ring (19) and guides upon the tensioning arm (7) and reaches the traveler (13) position without any hindrance.

12. The method as claimed in claim 10, wherein the traveler (13) rotates in an anticlockwise direction for yarn threading when the yarn break sensor (18) is placed in a right position of the cop (17) and the threading arrangement (1) is advanced at a left position of the cop (17).

13. The method as claimed in claim 10, wherein the traveler (13) rotates in a clockwise direction for yarn threading when the yarn break sensor (18) is placed in a left position of the cop (17) and the threading arrangement (1) is advanced at a right position of the cop (17).

14. The method as claimed in claim 10, wherein the rocker arm (4), the gripper arm (3) and the tensioning arm (7) move upwards and downwards along with the ring rail (9) in synchronization for hooking the end of the yarn (12).

15. The method as claimed in claim 10, wherein the yarn (12) is guided inside the balloon control ring (19) by tension and becomes available for subsequent piecing with delivery fibre from the drafting zone (16) of the ring spinning machine (10).

Drawing