Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H15/00—Piecing arrangements ; Automatic end-finding, e.g. by suction and reverse package rotation; Devices for temporarily storing yarn during piecing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H51/00—Forwarding filamentary material
  • B65H51/20—Devices for temporarily storing filamentary material during forwarding, e.g. for buffer storage
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
  • B65H2701/00—Handled material; Storage means
  • B65H2701/30—Handled filamentary material
  • B65H2701/31—Textiles threads or artificial strands of filaments

Definitions

• the present invention generally relates to a yarn piecing system for piecing auxiliary yarn when a yarn break occurs at a spinning station of a ring spinning machine. It also relates to a method for automatic piecing of auxiliary yarn at a spinning station.
• Known yarn piecing systems carry out an automatic piecing of a broken end of yarn.
• a yarn break occurs on a ring spinning machine, the broken end of yarn is wound on a bobbin after breakage.
• an automatic yarn handling device is used for detecting the broken end of the yarn by means of a suction tube connected to a vacuum source.
• the suction tube is mounted on an automatic service station arranged displaceable along a row of spinning stations with an option of stopping at a selected spinning station requiring a service operation.
• the yarn end is sucked into the vacuum tube by which the yarn end is positioned with respect to the bobbin and, subsequently, a threading operation is carried out by creating a threading section of the yarn end.
• the threading section is positioned at the flange of the ring and a traveller on the ring of the spinning machine is set into motion by compressed air so that it is put onto the threading section of the yarn end and the yarn end is threaded into the traveller.
• the yarn end is positioned by means of the same suction tube for piecing to roving issuing from roving delivery rollers.
• JP03199436A discloses one said known yarn piecing systems having an automatic service station which can be positioned at a spinning station for supplying a free end of auxiliary yarn from an auxiliary yarn source to a revolving spindle having a spindle tube providing a winding surface onto which the free end is to be wrapped.
• auxiliary yarn is supplied from a yarn feeding nozzle propelling the free end of auxiliary yarn together with air to the spindle tube of the revolving spindle.
• the system is also provided with a finger element to fasten auxiliary yarn on outside the yarn feeding nozzle to form a threading section once the free end of auxiliary yarn is wrapped onto the spindle tube.
• automatic handling means are provided to handle both the yarn feeding nozzle and the finger element to carry out the threading operation. Once threaded, the yarn end of the auxiliary yarn is positioned by means of another finger element for piecing it to roving issuing from front rollers of the drafting assembly.
• the yarn piecing system disclosed by JP03199436A has several shortcomings.
• One of said shortcomings is that of failure of the wrapping operation of the free end of auxiliary yarn to the spindle tube caused by poor adherence of the free end of auxiliary yarn to the surface of the spindle tube, in particular, when the spindle tube is empty of yarn after doffing.
• Another shortcoming is that the threading operation takes place while the spindle tube keeps rotating for an appropriate tension acts on the auxiliary yarn on outside the yarn feeding nozzle and prevents the threading section from sagging.
• the threading operation is even more difficult and complex to be carried out since threading demands high preciseness when positioning the yarn.
• the yarn processing and control means are configured to supply a signal to the control unit of the yarn buffer mechanism for the yarn buffer mechanism to form the yarn buffer including a predetermined length of auxiliary yarn at a launching step of the piecing cycle.
• processing and control means are configured
• a positioning sensor e.g., a laser sensor fixed in one end of the ring spinning machine
• the robotic arm When synchronization is done, the robotic arm starts following the movable support rail so that all the movements needed to carry out threading into a ring traveller will be merged with the movements of the tracking of the movable support rail.
• the yarn piecing system comprises yarn cutter means arranged on the yarn conveying path inside the yarn handling tool for cutting auxiliary yarn inside the yarn path of the yarn handling tool upon receiving a cutting signal from the processing and control means.
• the yarn cutter means may be configured by a small blade or cutter integrated on the yarn handling tool to be able to cut the auxiliary yarn in the yarn path inside the yarn handling tool so that the free end of the auxiliary yarn does not protrude outside the yarn nozzle of the yarn handling tool once cut.
• the blade or cutter may be driven by an electromagnet or air actuator.
• the yarn piecing system comprises yarn retaining means arranged on the same yarn conveying path inside the yarn handling tool to retain in place the auxiliary yarn on the path inside the yarn handling tool, for example, when the auxiliary yarn has been cut.
• the piecing system is prepared to carry out a yarn self-threaded procedure in case of yarn loss along the yarn conveying path inside the yarn handling tool.
• Yarn loss is detected by means of sensor means configured to detect presence and/or movement of the yarn inside the yarn handling tool.
• the sensor means are connected operatively to the processing and control means to inform the system about the state of the auxiliary yarn inside the tool.
• the yarn piecing systems comprises the yarn feeding device including; a yarn outlet of the yarn buffer mechanism,
• - yarn retaining means arranged to retain in place a free end of auxiliary yarn on outside the yarn outlet of the yarn buffer mechanism, and air blowing means arranged to inject air into the yarn outlet of the yarn buffer mechanism.
• the processing and control means are configured to carry out the automatic selfthread operation including the steps of; i. supplying a signal to the drive means of the robotic arm for the robotic arm to position the yarn inlet of the yarn handling tool in correspondence with the yarn outlet of the yarn buffer mechanism, ii. supplying an activation signal to the air blowing means of the yarn feeding device to blow the free end of auxiliary yarn on outside the yarn outlet of the yarn buffer mechanism while retaining in place the auxiliary yarn of the yarn buffer on outside the yarn outlet, and iii. supplying an activation signal to the yarn propelling means of the yarn handling tool for said free end of auxiliary yarn of the yarn buffer to be suctioned along the yarn conveying path inside the yarn handling tool.
• the claimed piecing system is suitable for using either with empty spindle tubes (after doffing) and with spindle tubes holding spun fibres (yarn package), since a free end of auxiliary yarn is always supplied to the spindle tube for wrapping.
• the claimed method and system have a hight reliability because at the launching phase a predetermined length of auxiliary yarn of the yarn buffer (i.e. , a controlled yarn length) is propelled to the yarn nozzle for the free end of the auxiliary yarn of the yarn buffer to be wrapped onto a revolving spindle tube.
• the yarn is preferably propelled towards a yarn contact area of the spindle tube that has been previously or simultaneously wetted with liquid, for example, with liquid spray or pulverized water.
• This yarn contact area may be an area of the spindle tube empty of yarn or an area of the spindle tube with existent yarn.
• the rate of success for the free end of auxiliary yarn to be wrapped onto the revolving spindle is significantly increased by wetting the yarn contact area intended to be contacted by the free end of auxiliary yarn at the launching step of the piecing cycle.
• the catching time is significantly reduced to an average time of three seconds versus an average time of nineteenth seconds when dispensing with the use of liquid spray.
• the reduction of time spent to grab the free end of yarn is particularly significative when the contact area of the spindle tube is empty of yarn (after doffing).
• - yarn supplying means for supplying a free end of auxiliary yarn to a spindle tube of a revolving spindle onto which said free end is to be wrapped, said yarn supplying means including a yarn nozzle for feeding a free end of said auxiliary yarn to the spindle tube of said revolving spindle,
• the system further comprises; liquid supply means arranged to be able to wet a yarn contact area of the revolving spindle intended to be contacted by the free end of auxiliary yarn at a yarn launching step of the piecing cycle, and processing and control means configured to supply an activation signal to the liquid supply means to supply liquid spray onto the yarn contact area of the revolving spindle tube before and/or while the free end of auxiliary yarn is propelled to the said yarn contact area of the revolving spindle.
• the liquid supply means comprise liquid spray means.
• the liquid may be pulverised or applied in any other way on condition that the yarn contact area of the revolving spindle is wet.
• the yarn contact area may be an area of the revolving spindle tube with yarn or an area of the revolving spindle empty of yarn.
• the automatic handling means include a yarn handling tool attached to a computer-controlled mechanical arm or robotic arm and both the liquid supply means and the yarn nozzle are arranged on the yarn handling tool.
• the yarn holding means are arranged on the yarn handling tool, and the processing and control means are configured to provide an activation signal to the drive means of the robotic arm for the yarn handling tool to carry out both threading and piecing operations once the free end of auxiliary yarn is wrapped onto the spindle and rotation of the spindle is stopped.
• the yarn piecing system comprises a yarn buffer mechanism to form a yarn buffer of auxiliary yarn along a yarn conveying path outside the yarn handling tool in between the yarn handling tool and an auxiliary yarn source, and a control unit for the yarn buffer mechanism.
• the processing and control means are configured to supply an activation signal to the yarn propelling means for said yarn propelling means to be able to propel the length of auxiliary yarn of the yarn buffer to the yarn nozzle for the free end of the auxiliary yarn of the yarn buffer to be wrapped onto a revolving spindle at a yarn launching step of the piecing cycle.
• a piecing cycle of the claimed method and system shall be understood to include both threading and piecing operations.
• Figure 3 shows a schematic perspective view of the yarn handling tool attached to the robotic arm with the yarn nozzle propelling the first length “L0” of auxiliary yarn of the yarn buffer and the liquid spray nozzle supplying liquid spray to wet the yarn contact area of the empty revolving spindle while the free end of auxiliary yarn is propelled to the said yarn contact area.
• Figure 4 shows a schematic perspective analogue to that of figure 2 wherein the yarn buffer mechanism is forming a yarn buffer of auxiliary yarn including a second length “L1” of auxiliary yarn which has been fed to the yarn path outside the yarn handling tool after the free end of the auxiliary yarn is wrapped and rotation of the spindle tube stopped. Movement back and forward of the yarn handling tool by the robotic arm will cause this second length “L1” of auxiliary yarn to increase or reduce to allow the threading operation to take place without sagging of the yarn and by preventing curls and twists from forming along the yarn path outside the yarn handling tool.
• Figure 5 is a perspective view of the yarn handling tool showing a threading section of auxiliary yarn formed on outside the yarn nozzle by means of a holding element (e.g., a grip) arranged on the yarn handling tool. Precise motion of the yarn handling tool is required for the yarn handling tool causes the holding element to hold or grasp the auxiliary yarn on outside the yarn nozzle to form the threading section. Once formed, the threading section must be threaded by a ring traveller mounted on a ring supported on the movable support rail of the corresponding spindle tube.
• a holding element e.g., a grip
• Figure 6 is a side view of the yarn handling tool of figure 1 attached to the robotic arm by means of an articulated joint configured to allow a tilting base of the yarn handling tool to pivot to an angled position to absorb heigh discrepancies of the working position of the movable support rail and to acquire an optimal work angle before carrying out threading.
• Figures 7a and 7b show a rear perspective view of the yarn handling tool approaching the movable support rail to touch it just enough to set by means of a tool angle sensor assembly the yarn handling tool at an optimal working position upon contacting the movable support rail.
• a controller unit of the robotic arm (not shown) is configured to check the status of the two proximity sensors arranged for detecting presence of the tilting base of the yarn handling tool.
• the controller unit of the robotic arm supply a setting up signal to the processing and control means (not shown) of the system for said processing and control means order synchronization of movement of the robotic arm with movement of the movable support rail according to a calculated height offset value applied to height position data provided by a positioning sensor (e.g., a laser sensor measuring heigh position of the movable support rail at one end of the ring spinning machine).
• a positioning sensor e.g., a laser sensor measuring heigh position of the movable support rail at one end of the ring spinning machine.
• Figure 8 shows a perspective view of the yarn handling tool attached to the robotic arm while the threading section of auxiliary yarn is about to be threaded by the ring traveller.
• An air conduct attached to the surface of the yarn handling tool propels air to move the ring traveller on the flange of the ring to facilitate threading.
• Figure 9 shows a schematic bottom view of the yarn handling tool showing the interior components arranged on the yarn conveying path inside the yarn handling tool for conveying the length of auxiliary yarn from the yarn inlet to the yarn outlet which is configured by way of the yarn nozzle.
• yarn propelling means there are arranged yarn cutter means, yarn retaining means and sensor means for detecting presence and/or movement of the length of auxiliary yarn.
• Figure 10 shows a schematic exploded view of the yarn handling tool from a bottom view.
• Figure 11 is a schematic bottom view of the yarn handling tool of figure 9 showing a detailed partial section of the portion of the yarn path inside the yarn handling tool wherein the yarn cutter is arranged for cutting the auxiliary yarn.
• This figure shows the piece of length of auxiliary yarn blown out of the yarn nozzle once it has been cut by the yarn cutter inside the yarn handling tool.
• the claimed yarn piecing system and method is provided for supplying automatic service to any spinning station of the ring spinning machine requiring repairment after yarn breakage.
• the claimed piecing system and method supply a free end of auxiliary yarn 1 to a revolving spindle having a revolving spindle tube 2 providing a winding surface onto which the free end is to be wrapped for the system subsequently carries out threading and piecing operations.
• the revolving spindles of the ring spinning machine are mounted aligned on a movable support rail 3 which moves up and down during spinning.
• a ring 4 is attached to the movable support rail 3 and a ring traveller 5 is movable mounted on a flange of the ring 4.
• Each revolving spindle is arranged coaxially in a vertical position with respect the ring 4 and a respective spindle tube 2 is placed on the revolving spindle to support a package of yarn formed by spinning in a well-known manner, resulting in the formation of a cop.
• the ring traveller 5 and the yarn threaded therein run round the spindle tube 2 on the flange of the ring 4 for the yarn is wound onto the surface of the spindle tube 2.
• Arranged above each revolving spindle tube 2 is a balloon constriction ring (not shown), a yarn guide (not shown) and a drafting assembly (not shown) including rear, middle and front drafting rollers from which drafted roving issues.
• the present invention provides a yarn piecing system and method wherein both threading and piecing operations are handled by means of a yarn handling tool 6 attached to a robotic arm 7 of an automatic service station including a carriage arrangement (not shown) on which the robotic arm 7 is mounted.
• the carriage is displaceable along the row of spinning stations of the ring spinning machine.
• a camera 29 is arranged on the robotic arm 7 operatively connected to an artificial vision system configured to check whether there are impediments to do the piecing. If the captured images found that something will compromise the piecing, the processing and control means of the system request the intervention of an operator to restore the normal working conditions for the yarn piecing system to be able to give automatic service.
• a yarn conveying path for conveying auxiliary yarn 1 from a yarn inlet 8 to a yarn outlet of the yarn handling tool 6 configured by way of a yarn nozzle 9.
• a yarn conveying path for conveying auxiliary yarn 1 from an auxiliary yarn source (not shown) to the yarn inlet 8 of the yarn handling tool 6.
• a yarn feeding device 10 is mounted on the same carriage arrangement and is configured for feeding a length of auxiliary yarn 1 to the yarn conveying path outside the yarn handling tool 6. This length of auxiliary yarn 1 outside the yarn handling tool 6 has been found to serve as a yarn buffer which helps to improve handling of the auxiliary yarn 1 on outside the yarn handling tool 6.
• the yarn feeding device 10 includes a yarn buffer mechanism 11 forming a yarn buffer of auxiliary yarn 1 along the yarn conveying path outside the yarn handling tool 6.
• the yarn buffer includes a first length “L0” of auxiliary yarn 1 which has been fed to the yarn path outside the yarn handling tool 6 for being propelled towards a revolving spindle tube 2 at a launching step of the piecing cycle (see, figure 2).
• the yarn buffer mechanism 11 includes a yarn holding member 12 configured and arranged to hold the auxiliary yarn 1 of the yarn buffer under elastic tension.
• This yarn holding member 12 includes a yarn holding rod operatively connected to a control unit (not shown) of the yarn buffer mechanism 11 to pivot an angle of rotation upon the control unit receives a signal coming from processing and control means of the system to form the yarn buffer.
• control unit of the yarn buffer mechanism 11 includes a stepper motor 13 operatively connected to the yarn holding rod for pivoting the yarn holding rod at different fixed positions to be able to take the necessary length of auxiliary yarn 1 from the auxiliary yarn source.
• the yarn processing and control means of the system supply a signal to the control unit of the yarn buffer mechanism 11 to form the yarn buffer with a predetermined length (e.g., the first length “L0”) of auxiliary yarn coming from the auxiliary yarn source.
• a predetermined length e.g., the first length “L0”
• the length of auxiliary yarn 1 of the yarn buffer necessary for launching may be different depending among others on the type of yarn to be pieced.
• the yarn piecing system To propel the predetermined length of auxiliary yarn 1 of the yarn buffer towards the revolving spindle tube 2 the yarn piecing system includes yarn propelling means arranged on the yarn path inside the yarn handling tool 6.
• the yarn propelling means comprise a Venturi tube and air injector assembly 14 arranged to suction air into the yarn inlet 8 of the yarn handling tool 6 upon receiving a signal from the processing and control means to propel the length of auxiliary yarn 1 of the yarn buffer through the yarn nozzle 9.
• the liquid supply means comprises a liquid spray nozzle 15 associated with a container of liquid (not shown) and with two solenoid valves (not shown) to control passage of liquid and air for pulverizing a small amount of liquid in a jet of air.
• the liquid spray nozzle 15 is arranged on the yarn handling tool 6 aligned vertically with the yarn nozzle 9 of the yarn handling tool 6 but rather may not be necessarily arranged on the yarn handling tool 6.
• Movement of the yarn handling tool 6 by the robotic arm 7 to carry out threading causes this second length “L1 ” of auxiliary yarn 1 to increase or reduce to allow this operation to take place without sagging and with the auxiliary yarn 1 outside the yarn handling tool 6 being kept under tension and free of curls.
• the stepper motor 13 is made to work at a lower current mode to keep the yarn holding rod to an elastic active working position while the auxiliary yarn 1 of the yarn buffer increases or reduces as the robotic arm 7 moves the yarn handling tool 6 back and forward. In the elastic active working position, the stepper motor 13 allows the yarn holding member 12 to acquire a partial retracted position when pulled by the movement of the robotic arm 7 resulting on the second length “L1” of auxiliary yarn 1 of the yarn buffer to be reduced.
• the tool angle sensor assembly 22 comprises at least two proximity sensors 23, 24 for detecting presence of the tilting base 21 of the yarn handling tool 6.
• Figure 10 shows these proximity sensors 23, 24 arranged on the rear part of a frame structure 25 of the yarn handling tool 6.
• Figures 7a and 7b show a rear perspective view of the yarn handling tool 6 approaching the movable support rail 3 to touch it just enough to set by means of the tool angle sensor assembly 22 the yarn handling tool 6 at the optimal working position upon contacting the movable support rail 3.
• the controller unit (not shown) of the robotic arm 7 is configured to check the status of two proximity sensors 23, 24 arranged for detecting presence of the tilting base 20 of the yarn handling tool 6.
• the controller unit of the robotic arm 7 supply a setting up signal to the processing and control means (not shown) of the system for said processing and control means order synchronization of movement of the robotic arm 7 with movement of the movable support rail 3 according to the calculated height offset value applied to height position data provided by the positioning sensor 19 (e.g., the laser sensor measuring heigh position of the movable support rail 3 at one end of the ring spinning machine).
• the processing and control means not shown
• the processing and control means order synchronization of movement of the robotic arm 7 with movement of the movable support rail 3 according to the calculated height offset value applied to height position data provided by the positioning sensor 19 (e.g., the laser sensor measuring heigh position of the movable support rail 3 at one end of the ring spinning machine).
• the robotic arm 7 starts following the movable support rail 3 so that all the movements needed to carry out threading into a ring 5 traveller will be merged with the movements of the tracking of the movable support rail 3. As stated, threading takes place without the spindle tube 2 is rotating to obtain maximum preciseness.
• the robot arm 7 moves the yarn handling tool 6 upwards and passes the yarn through the balloon constriction ring (not shown), and a yarn guide (not shown).
• a spindle brake (not shown) is released and the yarn handling tool 6 is raised until it takes the auxiliary yarn 1 up to the front rollers of the drafting assembly to carry out piecing of the auxiliary yarn 1 on the roving issuing the front rollers.
• a cutter 26 integrated on the yarn handling tool 6 cut the auxiliary yarn 1 in the path inside the yarn handling tool 6 so that the free end of the auxiliary yarn 1 does not protrude outside the yarn nozzle 9 once cut.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Spinning Or Twisting Of Yarns (AREA)
• Guides For Winding Or Rewinding, Or Guides For Filamentary Materials (AREA)
• Replacing, Conveying, And Pick-Finding For Filamentary Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=83232813

Family Applications (1)

Country Status (4)

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• 2022
  • 2022-09-30 JP JP2025512893A patent/JP2025529191A/ja active Pending
  • 2022-09-30 EP EP22798288.1A patent/EP4581200A1/de active Pending
  • 2022-09-30 CN CN202280099636.9A patent/CN119790194A/zh active Pending
  • 2022-09-30 WO PCT/EP2022/077314 patent/WO2024046587A1/en not_active Ceased

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