WO2019008421A1

WO2019008421A1 - Auto doffing system for draw texturing machines and air texturing machines

Info

Publication number: WO2019008421A1
Application number: PCT/IB2017/055199
Authority: WO
Inventors: Brij PATEL; Harshal PATEL; Hemendra VAKHARWALA; Rajneesh DHOLAKIA; Gaurang Patel
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-07-05
Filing date: 2017-08-30
Publication date: 2019-01-10
Anticipated expiration: 2020-01-05

Abstract

An automatic doffing and donning system for draw texturing and air texturing machines is disclosed. Doffing system includes a cradle system that includes a lift and lock mechanism that eliminates requirement of constant pneumatic pressure to hold isolated yarn packages; a landing slide mechanism that deploys a landing slide for yarn packages during ejection of the yarn packages, and retracts the landing slide when a new package tube is in contact with the take-up drum; and a pressure box for generation of ejection and locking movement of end caps of the cradle system that hold the package. Pressure box includes a single cylinder to generate ejection and locking movements of end caps. Cylinder drives a double sided rack that rotates two pinions. Nuts of ball and screw assemblies coupled to end caps get drive from the two pinions through wire ropes routed through pulleys.

Description

AUTO DOFFING SYSTEM FOR DRAW TEXTURING MACHINES AND AIR

TEXTURING MACHINES

TECHNICAL FIELD

[0001] The present disclosure relates generally to the field textile industry. In particular, the present disclosure pertains to doffing system for texturing machines.

BACKGROUND

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Doffing is an operation of removing bobbins, tube from cradles or other apparatus that hold yarn packages and replacing them with empty paper tubes or other types of tubes, and applying back yarn winding on empty tubes. Application of yarn winding on empty tubes is known in the art as donning/rethreading. Conventionally, human operators have been performing doffing and rethreading operations on draw texturised yarn (DTY) machines and air texturised yarns (ATY) machines. Manual intervention of doffing and rethreading operations reduces accuracy of these operations and leads to error of a few kilometres of yarn.

[0004] An automatic doffing process includes cutting the yarn after a pre-programmed quantity of material is deposited on the tube without stopping the thread line and donning/rethreading the blank tube that has replaced the full bobbin. Various devices and methods have been proposed in the art with a view to accomplishing the operation more efficiently so as to reduce downtime of respective working units during the doffing operation.

[0005] According to a known method of doffing, a full yarn package is first removed from a bobbin holder by a doffing device and discharged thereafter to a position where the yarn package does not interfere with subsequent loading of an empty tube, whereupon the empty tube is placed on the bobbin holder by any suitable means for donning/rethreading. Various issues are faced while using said method of doffing, such as relating to time interval after which packages are doffed, incomplete packages being doffed, errors related to manual intervention and other related issues. [0006] There is, therefore, a need to address above mentioned and other related issues, and provide an automatic doffing system for doffing yarn packages and donning blank tubes that overcomes the above mentioned problems.

[0007] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[0008] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term "about". Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0009] As used in the description herein and throughout the claims that follow, the meaning of "a," "an," and "the" includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of "in" includes "in" and "on" unless the context clearly dictates otherwise.

[00010] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. "such as") provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.

[00011] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

OBJECTS OF THE INVENTION

[00012] A general object of the present disclosure is to automate doffing and donning/rethreading processes on draw texturing machines and air texturing machines so that doffing operation can be done without presence of human operators.

[00013] Another object of the present disclosure is to provide a doffing system that increases accuracy of doffing and donning processes by reducing error in length of yarn.

[00014] Another object of the present invention is to provide a doffing system that prevents generation of excessively short packages.

[00015] Another object of the present invention is to provide a doffing system that can be accommodated in existing floor space of texturing machine without a need of an additional aisle.

[00016] Another object of the present invention is to provide a doffing system that allows removal of packages from the front side of the system for easy operation.

[00017] Another object of the present invention is to provide a doffing system that can be of retrofitted to existing machines with no or slight modifications.

[00018] Another object of the present invention is to provide a doffing system that reduces risk of accidents during manual end cap locking.

[00019] Another object of the present invention is to provide a doffing system with increased reliability of locking of end caps without use of pneumatic pressure.

[00020] Another object of the present invention is to provide a doffing system that collects yarn wastage without use of a separate suction blower. [00021] Another object of the present invention is to provide a doffing system that can accommodate more than one empty tubes.

[00022] Another object of the present invention is to provide a doffing system that reduces pneumatic air consumption.

[00023] Another object of the present invention is to provide a doffing system that uses a single acting cylinder for end cap locking.

[00024] Another object of the present invention is to provide a doffing system that does not require constant uninterrupted air pressure for locking packages from take-up drum.

[00025] Another object of the present invention is to provide a doffing system that isolates yarn packages from winding drum in case of yarn break and doffing to avoid damage to the package.

SUMMARY

[00026] Aspects of the present disclosure relate to a doffing system for texturing machines. In particular, they provide an automatic doffing and donning/rethreading system for draw texturing machines and air texturing machines that eliminates manual intervention.

[00027] In an aspect, the present disclosure provides an automatic doffing system for doffing of yarn packages and donning/rethreading of new empty tubes, wherein the automatic doffing system includes a cradle system that incorporates a lift and lock mechanism that eliminates requirement of pneumatic pressure to hold isolated yarn packages from a take-up drum, and a pressure box that incorporates a single pneumatic cylinder configured to provide translatory motion to a double sided rack coupled to two pinions. Actuation of the pneumatic cylinder generates ejection and locking pressure at end caps of the cradle system that hold the package. In an aspect, rotation of the two pinions due to translatory motion to the double sided rack generates pulling action respective wire rope/cable, and the pulling action is used to rotate nut of a ball and screw mechanism. Rotation of the nut of the ball and screw mechanism in turn generates linear motion of screw to provide lock or eject motion of the end caps. In an aspect, the respective wire ropes/cables are routed from the two pinions to the nuts of the two ball and screw mechanism at two ends through pulleys.

[00028] In an aspect, cradle system also includes a landing slide mechanism that deploys a landing slide for yarn packages during their ejection, and retracts the landing slide when an empty tube is in contact with the take-up drum. In an aspect, the landing slide mechanism allows removal of packages from winding side/front side of the cradle system.

[00029] The automatic doffing system further includes a tube feeding system that utilizes a single acting pneumatic cylinder to drive feed mechanism. In an aspect, use of a single acting cylinder reduces pneumatic air consumption and increases reliability of the doffing system. Further, the tube feeding system is configured to simultaneously accommodate two empty tubes. In an aspect, tube feeding system includes a tube cassette and the single acting pneumatic cylinder deploys a tube to the cradle from front tube cassette lips, and uses a spring mechanism for shifting spare tube into the front tube cassette lips.

[00030] In an aspect, the disclosed automatic doffing system further includes a yarn trapping, cutting and suction mechanism. The mechanism includes a solenoid coil-type cutter that eliminates use of pneumatic air for cutting the yarn. It traps moving yarn and cuts the trapped yarn by achieving an angle between a blade and a stopping face of the mechanism.

[00031] In an aspect, the disclosed automatic doffing system further includes a threading system that picks yarn from suction unit and delivers the picked yarn to cradle end cap for operation of next doffing sequence. The threading system includes a pneumatic cylinder with a rack and pinion mechanism to rotate a threading arm with specially profiled fingers to pick yarn from the suction unit and transport the picked yarn to end cap for rethreading.

[00032] In an aspect, a waste collection and storage device develops vacuum for suction of yarn using compressed air thereby doing away with requirement of an additional suction blower. It also enables yarn waste to be collected locally for each section.

[00033] In an aspect, the disclosed doffing system incorporates a control system comprising an ADS field card that derives different logical states of the doffing system depending upon the status of production on spindle. For example, when yarn production is in process a multi -function push button forcibly initiates doffing cycle, and resets doff time. The control system stores the timing data for each event individual in the doffing cycle and activates the doffing cycle after pre-programmed time is elapsed. This enables the doffing system to follow a random doffing pattern, wherein the individual yarn packages are doffed as and when a target material has accumulated in the yarn package.

[00034] In another aspect, control system further comprises a feedback system that provides a feedback on yarn breakage and activates doffing cycle. Thus, when production is halted due to yarn break and a yarn package is still on the spindle, the yarn package is ejected on package slide, and thereafter a new threading sequence is started.

[00035] In another aspect, the disclosed automatic doffing system to detect yarn break and operate doffing accordingly. Further, electronic feedback improves accuracy of doffing operation and reduces error in length of the yarn on a doffed package.

BRIEF DESCRIPTION OF THE DRAWINGS

[00036] The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[00037] FIG. 1A illustrates an exemplary representation of cradle system of the disclosed doffing system in accordance with an embodiment of the present disclosure.

[00038] FIG. IB illustrates an exemplary exploded view of the cradle system in accordance with an embodiment of the present disclosure.

[00039] FIG. 1C illustrates exemplary representation of pressure box of the cradle system in accordance with an embodiment of the present disclosure.

[00040] FIG. 2 illustrates exemplary representation of a tube feeding system in accordance with an embodiment of the present disclosure.

[00041] FIG. 3A illustrates an exemplary representation of a yarn trapping, cutting and suction mechanism in accordance with an embodiment of the present disclosure.

[00042] FIG. 3B illustrates an exemplary exploded view of suction device in accordance with an embodiment of the present disclosure.

[00043] FIG. 4 illustrates exemplary representation of a threading system in accordance with an embodiment of the present disclosure.

[00044] FIG. 5 illustrates exemplary representation of a package stopping system in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

[00045] In the following detailed description of exemplary embodiments of the invention, reference is made to the accompanying drawings that form a part hereof and, which show by way of illustration, specific exemplary embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It is to be understood that other embodiments may be utilized and that logical, mechanical, electrical and other changes may be made without departing from the spirit or scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

[00046] If the specification states a component or feature "may", "can", "could", or "might" be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.

[00047] 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).

[00048] Various aspects of the embodiments described above may be used alone, in combination, or in a variety of arrangements not specifically discussed in the embodiments described in the foregoing and is therefore not limited in its application to the details and arrangement of components set forth in the foregoing description or illustrated in the drawings. For example, aspects described in one embodiment may be combined in any manner with aspects described in other embodiments.

[00049] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.

[00050] Aspects of the present disclosure relate to a doffing system for texturing machines. In particular, they provide an automatic doffing and donning/rethreading system for draw texturing machines and air texturing machines that eliminates manual intervention. [00051] In an aspect, the present disclosure provides an automatic doffing system for doffing of yarn packages and donning/rethreading of new empty tubes, wherein the automatic doffing system includes a cradle system that incorporates a lift and lock mechanism that eliminates requirement of pneumatic pressure to hold isolated yarn packages from a take-up drum, and a pressure box that incorporates a single pneumatic cylinder configured to provide translator motion to a double sided rack coupled to two pinions. Actuation of the pneumatic cylinder generates ejection and locking pressure at end caps of the cradle system that hold the package. In an aspect, rotation of the two pinions due to translator motion to the double sided rack generates pulling action respective wire rope/cable, and the pulling action is used to rotate nut of a ball and screw mechanism. Rotation of the nut of the ball and screw mechanism in turn generates linear motion of screw to provide lock or eject motion of the end caps. In an aspect, the respective wire ropes/cables are routed from the two pinions to the nuts of the two ball and screw mechanism at two ends through pulleys.

[00052] In an aspect, cradle system also includes a landing slide mechanism that deploys a landing slide for yarn packages during their ejection, and retracts the landing slide when an empty tube is in contact with the take-up drum. In an aspect, the landing slide mechanism allows removal of packages from winding side/front side of the cradle system.

[00053] The automatic doffing system further includes a tube feeding system that utilizes a single acting pneumatic cylinder to drive feed mechanism. In an aspect, use of a single acting cylinder reduces pneumatic air consumption and increases reliability of the doffing system. Further, the tube feeding system is configured to simultaneously accommodate two empty tubes. In an aspect, tube feeding system includes a tube cassette and the single acting pneumatic cylinder deploys a tube to the cradle from front tube cassette lips, and uses a spring mechanism for shifting spare tube into the front tube cassette lips.

[00054] In an aspect, the disclosed automatic doffing system further includes a yarn trapping, cutting and suction mechanism. The mechanism includes a solenoid coil-type cutter that eliminates use of pneumatic air for cutting the yarn. It traps moving yarn and cuts the trapped yarn by achieving an angle between a blade and a stopping face of the mechanism.

[00055] In an aspect, the disclosed automatic doffing system further includes a threading system that picks yarn from suction unit and delivers the picked yarn to cradle end cap for operation of next doffing sequence. The threading system includes a pneumatic cylinder with a rack and pinion mechanism to rotate a threading arm with specially profiled fingers to pick yarn from the suction unit and transport the picked yarn to end cap for rethreading.

[00056] In an aspect, a waste collection and storage device develops vacuum for suction of yarn using compressed air thereby doing away with requirement of an additional suction blower. It also enables yarn waste to be collected locally for each section.

[00057] In an aspect, the disclosed doffing system incorporates a control system comprising an ADS field card that derives different logical states of the doffing system depending upon the status of production on spindle. For example, when yarn production is in process a multi -function push button forcibly initiates doffing cycle, and resets doff time. The control system stores the timing data for each event individual in the doffing cycle and activates the doffing cycle after pre-programmed time is elapsed. This enables the doffing system to follow a random doffing pattern, wherein the individual yarn packages are doffed as and when a target material has accumulated in the yarn package.

[00058] In another aspect, control system further comprises a feedback system that provides a feedback on yarn breakage and activates doffing cycle. Thus, when production is halted due to yarn break and a yarn package is still on the spindle, the yarn package is ejected on package slide, and thereafter a new threading sequence is started.

[00059] In another aspect, the disclosed automatic doffing system to detect yarn breaks and operates doffing accordingly. Further, electronic feedback improves accuracy of doffing operation and reduces error in length of the yarn on a doffed package.

[00060] FIGs. 1A to 1C illustrate exemplary representation of cradle system of the disclosed automatic doffing system in accordance with an embodiment of the present disclosure. The cradle system consists of a landing slide mechanism 102, a pressure box 104, and a lift and lock mechanism, wherein the landing slide mechanism 102 deploys a landing slide 116with help of a landing gear 138for sliding yarn packages during ejection of the yarn packages and retracts the landing slide 116 when paper tube is in contact with take-up drum. Further, landing slide mechanism 102 provides a slide to packages using gravitational potential energy to transfer the packages to a package holding area. Retraction of the slide is coupled with a left cradle arm 134 and a right cradle arm 136that eliminates use of any additional activation mechanism.

[00061] In an aspect, as illustrated in FIG. 1C, pressure box 104 utilises a single pneumatic cylinder 118attached to a double sided rack 120 of a rack and pinion mechanism that incorporates two pinions 122 for generation of locking and unlocking/ejection movement of end caps 112that hold the package. Rotational movement of the pinions 122 is transferred to two nuts of two ball and screw mechanisms 114 configured at two ends, using pulleysl24 and wire rope /cablesl26 (refer FIG. 1 A). Screws of the ball and screw mechanisms 114 are connected to end caps 112 at respective ends. Thus the end caps 112 move back and forth with rotation of nut of the ball and screw mechanism 114 in one or other direction to either hold the package or eject the package. In an embodiment, the wire rope /cables 126 can be routed from pinions 122 to the respective nuts of the ball and screw mechanisms 114 using pulleys placed at appropriate places, and it is to be appreciated that position of the wire rope /cables 126 shown in FIG. 1 A is only symbolic.

[00062] In an aspect, the lift and lock mechanism includes a pneumatic cylinder 128 and a locking cam 130, and is configured to lift the package to isolate it from take-up drum to enable alignment of paper tube feeding device with the take-up drums before exchange of paper tube between paper tube feeding device and cradle system. In an aspect, this is done without constant pneumatic pressure using spring tension and locking cam 130. In an aspect, the lift and lock mechanism is also configured to isolate the package in case package diameter exceeds a safety limit, and this is also done without requirement of pneumatic air pressure using spring tension and locking cam 130. In an aspect, locking cam 130includes a cut-out in which package cam follower gets locked to hold the package. Further, the lift & lock mechanism is used to hold the isolated package from take-up drum without the requirement of constant air pressure.

[00063] In an aspect, end caps 112 can be provided with one or more of tapered heads for automatic centring of package/paper tubes and packages, slipping braking rings to stop rotation of rotating packages, a metallic shell to allow packages slip on end cap 112 while braking, and a bearing housing for snug fit of bearings.

[00064] In an aspect, a brake lever mechanism 108 is used to stop rotation of a rotating package wherein brake lever mechanism 108 is fitted with a spring lever assembly to allow end cap 112 opening when brakes are engaged. The brake lever mechanism 108 can be configured with to rsional spring to keep the brakes disengaged in normal state. Braking cam 110 is configured to activate brake lever mechanism 108 when the package is lifted and is used for de-activating brake lever mechanism 108 when package is engaged with the take-up drum. Taper cam 132 can also be adjusted to build packages with different taper angles as desired by user of the machine. In an aspect, right cradle arm 134 and left cradle arm 136 are designed to put all these components together to provide a compact cradle system that can allow efficient doffing as well as donning operations.

[00065] FIG. 2 illustrates an exemplary representation of tube feeding system in accordance with an embodiment of the present disclosure. The tube feeding system consists of a paper tube cassette 202 that uses a single lockable spring loaded cylinder 210 to move the cassette 202 from position A to position B (as shown in FIG. 2). Thepaper tube cassette 202 includes a top paper tube cassette lip 204 and bottom paper tube cassette lip 208 to grip more than one empty paper tubes such as one tube on front side of the lips 204/208 and another spare tube on rear side of the lips 204/208. The paper tube cassette 202 is configured with a spring mechanism for retracting paper tube cassette 202 from position B to position A and to shift a spare tube from rear side of the top paper tube cassette lips 204/208 to front side. In an aspect, the paper tube cassette 202 also includes retractable tube guides 206for constant alignment of paper tubes with the cradle for consistent exchange and changes its position with respect to the position of the paper tube mechanism. As can be seen, the paper tube cassette 202 incorporates provision to store and lock more than one paper tubes in a limited space.

[00066] In an aspect, top paper tube cassette lip 204 and bottom paper tube cassette lip 208 are configured to hold paper tube ready for exchange with the cradle. Further, rear side of paper tube cassette lips 204/208 are configured to receive new tubes by an operator and hold them during exchange that provides one way locking of the paper tube.

[00067] In an aspect, the tube lip locking mechanism locks the movement of lower lips 208 when paper tube feed assembly 202 is in position B using a spring loaded locking pin to avoid over throwing of paper tube while operator is re loading the empty cassette with blank tubes.

[00068] FIG. 3A illustrates exemplary representation of a yarn trapping, cutting and suction mechanism in accordance with an embodiment of the present disclosure. The yarn trapping, cutting and suction mechanism consists of a yarn trapping and cutting device 302 that can trap moving yarn into the system and can cut the moving yarn by achieving an angle between a cutter blade 304 and a stopping face 306.

[00069] In an aspect, the yarn trapping and cutting device 302 is designed to avoid manual intervention of blade 304 for safety, and the yarn trapping and cutting device 302 is provided with a solenoid308 that improves flexibility of trapping and cutting operations. The blade 304 is designed with a special cutting geometry and is made up of selected material for clean cut of various yarn types. A top angle plate 310 provides mounting of the blade 304 to achieve an angle in the range for 15 to 21 degrees between running yarn and blade 304. In an aspect, the solenoid 308 provides air connections to solenoid valves in limited space.

[00070] In an aspect, the yarn trapping and cutting device 302 is supported by a plate 314 that allows efficient cutting of yarn packages and houses the yarn trapping and cutting device 302 and suction device 312.

[00071] In an aspect, the discloses automatic doffing system is configured with a waste collection and storage device, wherein a suction device 312 consists of a vacuum system where positive air pressure is converted into vacuum pressure using HV disc which works on the principle of venturi effect. The vacuum pressure is used to suck the yarn through an inlet pipe and send it to sectional waste collection bins through an outlet pipe. The waste collection device consists of sectional waste collection trays for storage of yarn waste, wherein the waste collection trays can slide out for easy removal of the yarn waste. In an aspect, suction device 312 allows running yarn to be sucked in a way that allows efficient trapping and cutting of the yarn with the help of the cutter blade 304 and the stopping face 306.

[00072] FIG. 3B illustrates an exemplary exploded view of suction device in accordance with an embodiment of the present disclosure. As shown, the suction device 312 comprises a HV disc 353, an inlet pipe 351 and an outlet pipe 354. The HV disc 353 can have number of slots such as 2 - 12 slots and work to generate vacuum for suction of waste thread through the inlet pipe 351. The sucked waste thread is sent to waste collection bins through the outlet pipe 354.

[00073] FIG. 4 illustrates exemplary representation of a threading system in accordance with an embodiment of the present disclosure. The threading system consists of threading arm 404 and specially profiled threading fingers 406 that can pick yarn from suction device 312 (as shown in FIG. 3) at position P and deliver the yarn to cradle end cap 112 at position Q. The system also achieves position R for trapping the yarn in traverse guide of winder. Threading system includes a single acting pneumatic cylinder 402 with a rack 408 and pinion 410 mechanism to rotate threading arm 404, wherein a spring 412is configured with the rack 408 and pinion 410 mechanism to implement reverse rotation of the threading arm 404. The threading arm 404 uses specially profiled fingers 406 to pick yarn from suction device 312 at position P, transport it to cut nose end cap 112 for rethreading at position Q, and leave/release the yarn and engage the yarn in a traversing guide at position R. The threading system can also put a tail end on the package when the package is at position Q.

[00074] FIG. 5 illustrates an exemplary representation of a package stopping system in accordance with an embodiment of the present disclosure, wherein package stopper 502 and 504are configured to stop a yarn package from sliding off and hold it without damaging the yarn package. A release lever 506 can be shifted from position X to position Y which moves the package stopper 502 and 504 to position Y.

[00075] In an aspect, the package stopping system uses a wire rope 508 to transfer force from lever 506 to corresponding package stopper 504 and hence enables a release of package from slide of the cradle system.

[00076] While embodiments of the present disclosure have been illustrated and described, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE INVENTION

[00077] The present disclosure automates doffing and donning/rethreading processes on draw texturing machines and air texturing machines eliminating need for presence of human operators.

[00078] The present disclosure provides a doffing system that increases accuracy of doffing and donning processes by reducing error in length of yarn.

[00079] The present disclosure provides a doffing system that prevents generation of excessively short packages.

[00080] The present disclosure provides a doffing system that can be accommodated in existing floor space of texturing machine without a need of an additional aisle.

[00081] The present disclosure provides a doffing system that allows removal of packages from the front side of the system for easy operation.

[00082] The present disclosure provides a doffing system that can be of retrofitted to existing machines with no or slight modifications. [00083] The present disclosure provides a doffing system that reduces risk of accidents that occurred due to manual end cap locking.

[00084] The present disclosure provides a doffing system with increased reliability of locking of end caps without use of pneumatic pressure.

[00085] The present disclosure provides a doffing system that collects yarn wastage without use of a separate suction blower.

[00086] The present disclosure provides a doffing system that can accommodate more than one empty tubes.

[00087] The present disclosure provides a doffing system that reduces pneumatic air consumption.

[00088] The present disclosure provides a doffing system that uses a single acting cylinder for end cap locking.

[00089] The present disclosure provides a doffing system that does not require constant uninterrupted air pressure for locking packages from take-up drum.

[00090] The present disclosure provides a doffing system that isolates yarn packages from winding drum in case of yarn break and doffing to avoid damage to the package.

[00091] The present disclosure provides a doffing system that carries out rethreading/donning process without human intervention which ensures consistent tail ends.

[00092] The present disclosure provides a doffing system that does the rethreading/donning process without human intervention which eliminates damages to end caps on account of operational mistakes during manual operations.

[00093] The present disclosure provides a doffing system which does the rethreading/donning process without human intervention which caused damages to traverse guides due to manual operational mistakes.

Claims

We Claim:

1. An automatic doffing system for implementing doffing and donning/rethreading operations, wherein the doffing system comprises:

a cradle system that includes:

a lift and lock mechanism that eliminates requirement of constant pneumatic pressure to hold isolated yarn packages from a take-up drum;

a landing slide mechanism that deploys a landing slide for yarn packages during ejection of the yarn packages, and retracts the landing slide when a new package tube is in contact with the take-up drum; and a pressure box for generation of ejection and locking movement of end caps of the cradle system that hold the package; and

a tube feeding system configured to simultaneously accommodate more than one empty tube.

2. The doffing system as claimed in claim 1, wherein pressure box utilizes a single cylinder to generate ejection and locking movements of the end caps; wherein the single cylinder is attached to a double sided rack of a rack and pinion mechanism, the double sided rack driving two pinions to provide rotational movement for ejection and locking movement of the two end caps at two ends.

3. The doffing system as claimed in claim 2, wherein the end caps are coupled to respective screws of two ball and screw assemblies, wherein respective nuts of the two ball and screw assemblies get drive from the two pinions through respective wire ropes routed through pulleys.

4. The doffing system as claimed in claim 1, wherein the end caps incorporate one or more of tapered heads for automatic centering of the package tubes and the packages; and further includes slipping braking rings to stop rotation of rotating packages.

5. he doffing system of claim 4, wherein the end caps are configured to accepts paper tubes with external diameter of 63 mm and above, and length of 275 - 280 mm and above.

6. The doffing system as claimed in claim 1, wherein the landing slide mechanism allows removal of packages from winding side/front side of the cradle system.

7. The doffing system as claimed in claim 1, wherein the cradle system includes a right cradle arm and a left cradle arm that hold the lift and lock mechanism, the landing slide mechanism ,the pressure box and the end caps to provide a compact cradle system.

The doffing system of claim 1, wherein the tube feeding system comprises a tube cassette and a single acting pneumatic cylinder; wherein the single acting pneumatic cylinder is used to move the tube cassette to a position for deploying an empty tube to the cradle system, and the tube cassette is returned back by a spring mechanism. The doffing system of claim 8, wherein the tube cassette incorporates a top tube cassette lip and a bottom tube cassette lip to hold more than one spare tubes, wherein front side of the top tube cassette lip and a bottom tube cassette lip is used for deploying a new tube to the cradle system, and a spare tube held on rear front side of the top tube cassette lip and a bottom tube cassette lip is moved to front side by the spring mechanism.

The doffing system of claim 9, wherein rear side of the top tube cassette lip and the bottom tube cassette lip is configured to receive new tubes by an operator and hold them during exchange.

The doffing system of claim 10, wherein the tube is guided till the exchange point to avoid miss alignment.

An automatic doffing system for implementing doffing and donning/rethreading operations, wherein the doffing system comprises:

a cradle system that includes:

a landing slide mechanism that deploys a landing slide for yarn packages during ejection of the yarn packages, and retracts the landing slide when a new package tube is in contact with the take-up drum; and

a pressure box for generation of ejection and locking movement of end caps of the cradle system that hold the package; and

a tube feeding system configured to simultaneously accommodate more than one empty tube; and

a yarn trapping, cutting and suction mechanism configured to trap moving yarn, cut the yarn and suck waste yarn to dispose the waste yarn into a waste collection and storage device, wherein a suction device configured to suck the waste yarn uses compressed air to create suction based on venturi effect.

The doffing system of claim 12, wherein the moving yarn is cut using a solenoid coil- type cutter that traps moving yarn and cuts the trapped yarn by achieving an angle of 15 to 21 degrees between a blade and a stopping face of the mechanism.

The doffing system of claim 12, wherein the doffing system further comprises a threading system that picks yarn from the suction unit and delivers the picked yarn to one of the end caps, wherein the threading system includes a pneumatic cylinder and a rack and pinion mechanism to rotate a threading arm having specially profiled fingers to pick yarn from suction unit and transport it to the end cap for rethreading. An automatic doffing system for implementing doffing and donning/rethreading operations, wherein the doffing system comprises:

a cradle system that includes:

a landing slide mechanism that deploys a landing slide for the yarn packages during ejection of the yarn packages, and retracts the landing slide when a new package tube is in contact with the take-up drum; and

a tube feeding system configured to simultaneously accommodate more than one empty tube;

a yarn trapping, cutting and suction mechanism configured to trap moving yarn, cut the yarn and suck waste yarn to dispose the waste yarn into a waste collection and storage device, wherein a suction device configured to suck the waste yarn uses compressed air to create suction based on venturi effect; and

a control system to control operation of the doffing system, wherein the control system incorporates a feedback system to detect breakage of yarn and release the yarn package

The doffing system of claim 15, wherein the control system stores timing data each event in doffing cycle and activates the doffing cycle after preprogrammed time is elapsed.

7. The doffing system of claim 16, wherein the doffing system follows a random doffing pattern, wherein the individual yarn packages are doffed as and when a target material has accumulated in the yarn package.