Method of operating a ring spinning machine, a ring spinning machine, and a kit for retrofitting a ring spinning machine

Abstract

The invention is directed to a method of operating a ring spinning machine, wherein a yarn runs between a nip point of a pair of exit rollers of a drafting system, through at least one vertically moveable yarn guide 3 and a traveler which runs on a ring being arranged on a vertically movable ring rail 2, and is twisted, and for cops building wound on a tube 5 having a length which is placed on a spindle, wherein during cops building between the ring rail 2 and the yarn guide 3 a spinning balloon 4 with a height is built; and wherein at least the ring rail 2 is vertically moved relative to the yarn guide whereby the height of the spinning balloon 4 is determined and wherein an initial position of the yarn guide 3 is selected in such a way, that the built spinning balloon 4 has a height of 30 – 32 mm plus the length of the tube 5, and wherein the initial position is kept during the initial phase of the cops building process, especially until the first 15 % - 40 % of the cops building process are completed.

Description

[0001] Method of operating a ring spinning machine, a ring spinning machine, and a kit for retrofitting a ring spinning machine

[0002] Technical Field of the Invention

[0003] The invention relates to the field of ring spinning and a method for reducing thread tension during the process of ring spinning, a ring spinning machine for carrying out the method, and a kit for retrofitting a ring spinning machine.

[0004] State of the art

[0005] It is known in the technical field of ring spinning, that thread breaks often occur at the beginning of the ring spinning process, more accurate at the beginning of the process of cop building. These early thread breaks are cumbersome to be fixed / pieced because at this stage of the cops building process only little thread is wound on the tube, which is arranged on the rotating spindle. The operator or the service robot first needs to find out, whether enough yam is in place to resume the ring spinning process by pulling the end of the broken yam wound on the tube towards the drafting unit. In case too little yam is in place the use of auxiliary yam is practiced, whereby the auxiliary yam is wound on the tube, cut and the so generated yam end is then pulled up to the drafting unit for resuming the ring spinning process. Alternatively, the residual yam on the tube (small amount) is cleaned from the tube and the ring spinning process is started all over again.

[0006] In praxis most yam breaks occur after doffing, i. e. at the very beginning of the ring spinning process / the beginning of the cops building process. As it is known, that the higher the tension on the yam is, the higher the risk for yam breakage is, a ring spinning method that allows for reduction of yam tension at the traveler of the ring / traveler system is required. It is further known, that the broader and higher the spinning ballon, which is created during the spinning process between the ring respectively the traveler and the yam guide, is , the higher the yam tension at the traveler is. To avoid a too broad spinning balloon one or more balloon restriction rings are used.

[0007] To decrease the heights of the spinning balloon methods of multiple balloons are applied. Yarn breakages need to be avoided at any stage of the ring spinning process since they are time consuming to be fixed and do have a negative impact on the down-stream winding process.

[0008] A too high yam tension has not only a negative influence on the number of yarn breakages but also limits the spindle speed possible to be used, limits the choice of traveler to be used and has a negative effect on the lifetime of the traveler.

[0009] Description of the Invention

[0010] The invention aims to provide a solution for reducing the number of yam breakages in general and specifically at the beginning, the initial phase of the cops building process. Further the invention aims to provide a solution that allows for higher spindle speed, increase of life of traveler and even the possibility to use of a lighter traveler.

[0011] This is achieved by a method for operating a ring spinning machine according to the independent claim 1 .

[0012] Accordingly the essence of the invention lies in a method of operating a ring spinning machine according to which a yam runs between a nip point of a pair of exit rollers of a drafting system, through at least one a vertically moveable yam guide, and a traveler, which runs on a ring being arranged on a vertically movable ring rail and is twisted and for cops building wound on a tube having a length which is placed on a spindle. Depending on the type of yam produced on the ring spinning machine the tube has a specific length. During the process of cops building a spinning balloon is built between the ring and the yam guide. The spinning balloon having a height that changes during the process of cops building. This change of spinning balloon height is caused by the relative movement between the vertically moveable yam guide and the ring respectively the ring rail. The relative movement is caused by at least the ring rail being vertically moved relative to the yam guide. The spinning balloon height is determined by this relative movement. In an initial phase of the cops building process a vertical position, i. e. an initial position, of the yam guide is set in such a way, that the built spinning balloon has a height of 30 to 32 mm plus the length of the tube used. This initial position is kept during the initial phase of the cops building process until the initial 15 to 40 % of the cops building process is completed. Since the ring rail is vertically - along the spinning axis which basically corresponds to the spindle axis - moving the initial height of the spinning balloon varies but does not exceed the maximum of tube length plus 30 to 32 mm. The length of the tube in the context of the height of the spinning balloon is to be understood as - from the perspective of standing in front of the ring spinning machine / spinning unit of the ring spinning machine - the length of the tube that vertically extends above the ring at the rings respectively the ring rails lowest position / initial position. This may correspond to the actual length of the tube but can be shorter than the actual length of the tube and depends on the arrangement of the spindle relative to the ring rail etc.. In other words the yam guide is positioned so that there is a distance of 30 to 32 mm between the yam guide and the top of the tube.

[0013] The spindle is arranged on a spindle rail and during the ring spinning process, the cops building process is rotating. On the spindle a tube is placeable in the sense of non-rotat- ably fixed thereto.

[0014] In the context of the invention the cops building process is defined as the process of ring spinning which results in a full cops, i. e. 100% of the cops building process are completed, with its distinct optical form, which is then doffed. The cops consists of three visually distinct parts, namely the curved base, the cylindrical middle section and the tapered tip and is built up layer for layer by yam passing the traveler running on the ring while the ring rail (or in certain ring spinning machines the spindle itself) being vertically moved along the spinning axis. This process is called cops building process.

[0015] The drafting system may include a compacting unit.

[0016] The spinning balloon having a height is built by the yam running between the yam guide and the traveler on the ring and its heights is measured from the ring to the yam guide. The spinning balloon is built only when the spindle is in motion, i. e. rotation. For simplicity the position of the ring and the ring rail are treated equally in this text. For the same reason the measurement of the traveler running on the ring, which also influences the heights of the spinning balloon, is not mentioned. Basically when talking about the position of the ring rail the ring and traveler are included and of the same position.

[0017] To define the initial spinning balloon height, the setting of the height of the yam guide relative to the ring respectively the ring rail is decisive. The initial spinning balloon height is chosen to be shorter than it is in the state of the art, i. e. according to a convention setting. According to the state of the art the initial balloon height is the length of the tube plus 37 mm. The disclosed initial setting of the spinning balloon height of the length of the tube used plus 30 - 32 mm results in a shorter balloon and therefore in lower yarn tension which further results in less yam breakages and allows for higher spindle speed. A reduction of yam breakages in the initial phase of the cops building process of up to 40% is achieved by selecting the initial spinning balloon height measured from the initial position of the ring rail as follows: length of the tube used plus 30 - 32 mm, preferably 30 mm. Generally speaking, the setting of the initial spinning ballon height, i. e. smaller than the length of the tube plus 37 mm has a positive effect.

[0018] The balloon height is meant to be the nominal height the spinning balloon has in the initial phase of the cops building process - due to the continuous vertical movement of the ring rail during the cops building process (building layers) this height slightly changes with every vertical movement of the ring rail along the spinning axis, which corresponds to the spindle axis.

[0019] During the initial phase of the cops building process - i. e. the first 15 - 40 % of the cops building process - the yam guide does not execute any vertical movement but remains at its initial position, namely at a height measured from the ring to the yam guide of tube length plus 30 - 32 mm while the ring rail is in its initial position. This setting results in a shorter balloon height than in conventional settings for the first 15 - 40% of the cops building process and helps to reduce the tension on the yam and because of the lower tension on the yam helps to run the traveler in a more constant and smoother manner on the ring increasing its lifetime or allows for the use of a lighter traveler.

[0020] The achieved reduction of number of yam breakages after e. g. the doffing of the ring spinning machine saves labor and money. The yarn guide may be arranged on a yam guide shaft which extends along a side of the ring spinning machine or sections thereof. Such yam guide shaft comprises several yam guides attached to it. The yam guide shaft is designed and arranged on the ring spinning machine in way that allows for vertical displacement of the attached yam guides along the spinning axis. The yam guide shaft is arranged horizontally parallel to the ring rail and vertically moves relatively to the ring rail. So the vertical movement of the yam guide is effectuated by the vertical movement of the respective yam guide shaft.

[0021] In an advantageous embodiment of the invention after completion of the first 15 - 40 % of the cops building process a vertical movement of the yam guide relative to the ring rail is initiated. This vertical movement results in a variation of the spinning balloon height. The so achieved spinning balloon height is still shorter than in conventional ring spinning methods, standard settings so to say, used and results in a lower yam tension. The vertical movement of the yam guide may be initiated after completion of 39 %, after 38 %, after 37 %, after 36 %, after 35 %, after 34%, after a third of the cops building process, after 33% and so forth of the cops building process. As mentioned already, the vertical movement of the yam guide is effectuated by the vertical movement of the yam guide shaft, if such shaft is present.

[0022] In a preferred embodiment of the invention after completion of the first 17 - 30 % of the cops building process a vertical movement of the yam guide relative to the ring rail is initiated. The initiation of the vertical movement of the yam guide consists of moving the yam guide further up towards the drafting unit. The initiation of the vertical movement of the yam guide after completion of the first 17 - 30% of the cops building process results in a shorter balloon height and correspondingly in a lower yam tension during the first 17 - 30 % of the cops building process and up to 40 % less yam breakages in this phase of the cops building process, as tests show. Since at the end of the cops building process according to the claimed method of operating a ring spinning machine the yam guide should be at the same final position as in a process carried out according to a commonly used method of operating a ring spinning machine the vertical movement of the yam guide is initiated after the completion of 17 - 30% of the cops building process. The vertical moment of the yarn guide results in a steady approximation to the yam guide position in a ring spinning method commonly used resulting in the same position only at the very end of the cops building process. This means, that the balloon height is during the whole cops building process shorter than in conventional ring spinning methods respectively the settings used in conventional ring spinning methods.

[0023] The ring rail and the yarn guide are moved relatively to each other, and the ballon height decreases steadily but is still shorter that in commonly used methods of operating a rind spinning machine. As a matter of facts this results in a lower yam tension compared to methods of operating a ring spinning commonly used. Commonly used methods of operating a ring spinning are defined in the context of the invention by the settings of the ring rail position and the yam guide position at a specific time in the ring spinning process respectively the cops building process.

[0024] In an even more preferred embodiment of the invention the vertical movement of the yam guide relative to the ring rail is initiated after the completion of the first 30 - 40 % of the cops building process. This results in no movement of the yam guide respectively the yam guide shaft for a long time, which results in lower energy consumption and of course, lower tension on the yam. Depending on the embodiment of the method the vertical movement of the yam guide respectively the yam guide shaft may start after completion of of 33 - 35 % of the cops building process, or after 36 - 38 % of the cops building process, and so forth.

[0025] According to an advantageous embodiment of the invention the relative movement between the ring rail and the yam guide is carried out in a ratio 1 :0.75. As soon as the yam guide is vertically moved, i. e. after 15 - 40 % or 17 - 30% or 25 - 28 % of the cops building process this ratio is maintained until the cops, the ring spinning cycle, is finished and results in the yam guide being at the same end position as it would be using a conventional ring spinning method. This is advantageous since after the completion of the cops building process, when the ring spinning cycle is finished and the cops is full the full cops needs to be doffed, i. e. removed from the spindle and replaced with an empty tube. Nowadays this is done automatically and due to the same final position of the yam guide as in conventional ring spinning methods / setting no changes in the doffing process are necessary. According to an advantageous embodiment of the invention during the final cops building process the balloon height reaches 115 - 120 mm, especially 118 mm.

[0026] This balloon height corresponds to the balloon height reached in a conventional ring spinning method / setting. This position is reached by raising the yam guide up to around 112-106 mm, preferably 108 mm above the tube, while the ring rail is at a position of around 165 mm.

[0027] In an advantageous embodiment of the invention the yarn runs through at least one balloon restricting ring. This results in even less tension on the yarn.

[0028] The essence of the invention further lies a ring spinning machine capable of carrying out the method as claimed in claims 1 - 7. The ring spinning machine comprises several spinning units, each of which comprises the common spinning components like drafting unit, spindle on a spindle rail, ring and traveler on a ring rail, yam guide arranged on a yam guide shaft, in some cases a least one balloon restriction ring. Some parts of the ring spinning machine are designed to be activated for all spinning units at at least one section of the ring spinning machine or at at least one side of the ring spinning machine such as the ring rail, the spindle rail and the yam guide shaft. The here described ring spinning machine comprises means or adaptations to means that allow for the carrying out of the method according to the invention, especially in the gear box of the ring rail and yam guide shaft. E. g. the ring spinning machine comprises a lifting tape for the yam guide respectively the yam guide shaft that is positioned on the pulley of the gear box in such a way, that allow for carrying out the method as described above and according to the invention. The used lifting tape is longer that the lifting tapes for the yam guide shaft of conventional ring spinning machines. As a result a movement of the yam guide respectively the yam guide shaft relative to the ring rail of a ratio of 1 :0.75 (whereas in conventional settings the ratio is around 1 :0.46) is achieved. This ratio may vary depending on the start of the vertical movement of the yam guide and the chosen initial position of the same. This is because the final position of the yam guide respectively the yam guide shaft is determined, i. e. the same as it is in conventional settings to allow e. g. automatic doffing. Basically, it may be at a range of 1 :0.5 - 0.8, e. g.

[0029] 1 :0.73 or 1 :0.72 or 1 :0.77 or 1 :0.78 and so forth. The ring spinning machine may comprise the components of the kit as described below, in the context of a kit for retrofitting a ring spinning machine.

[0030] The essence of the invention is a kit for retrofitting a ring spinning machine in order to be operable according to a method as claimed in claims 1 - 7 comprising at least a lifting tape. The lifting tape is longer than it is for the conventional setting or conventional ring spinning machines, e.g. at least 5 - 7 mm longer than the conventional lifting tapes. The length, however, depends on the position of the lifting tape on the pulley. The pulley is arranged in a gear box and controls the vertical movement of the yam guide, respectively the yarn guide shaft several yarn guides for serval spinning units are arranged on. The diameter of the pulley defines the speed of the vertical movement of the yarn guide respectively the yarn guide shaft the yarn guides are arranged on and is therefore chosen to be of a diameter allowing a vertical movement of the ring rail and the yarn guide in a ratio 1 : 0.75, or, depending on the settings in a range of 1 : 0.5 to 0.8. The lifting tape needs to be of a length that is adapted to the diameter of the pulley so that initial position of the yarn guide, respectively the yam guide shaft and the

[0031] The Kit may according to an embodiment of the invention further comprising a pulley and a stopper.

[0032] The pulley is of a diameter supporting a movement of the ring rail and the yam guide tube according to the invention.

[0033] The stopper is to be arranged in a way that allows to control the vertical movement of the yam guide, respectively the yam guide shaft to start moving only after completion of 15 - 40 % of the cops building process. It restricts the yam guide shaft from lowering below the initial setting, the initial height of 30 - 32 mm vertically above the top of the tube mounted on the spindle. The kit may further comprise a spacer for achieving the desired ration between the ring rail to yam guide shaft movement of e.g. 1 : 0.75 and a clamping piece for guiding or positioning the lifting tape on the spacer.

[0034] The kit may further comprise a first clamping piece for clamping the lifting tape to the stopper, and a second clamping piece for positioning the lifting tape on a spacer, a spacer for achieving the desired ratio of the movement of the ring rail versus the yam guide shaft, a roller rest for fixing the guiding rollers to guide the lifting tapes for the yam guide as well as for the ring rail, a clamping lug for connecting the lifting tape to the gear box shaft, a cam for activating the ring rail top and bottom safety limit switches and a limit switch bracket for mounting the limit switches.

[0035] Apart from the listed machine parts the kit further comprises an installation manual giving the exact specifications on how to install the kit as well as an operation manual giving the exact specifications on how to operate a ring spinning machine according to the herein described method.

[0036] Short description of the drawings

[0037] Further advantages of the invention are described in the following embodiments. They show, in each case schematically:

[0038] Fig. 1 shows a comparison of ring spinning units of a ring spinning operating according to a conventional method and a ring spinning units operating according to an embodiment of the invention.

[0039] Fig 2 shows a diagram comparing the balloon height reached in a method of operation a ring spinning machine according to the state of the art and in a method according to an embodiment of the invention.

[0040] Fig 3 shows a gear box with the lifting tape for the yam guide installed.

[0041] Fig. 1 shows different spinning units 1 in different phases of the cops building process. The spinning units 1 show a ring rail 2 with a ring arranged onto it, the traveler is not shown, a yam guide 3, a tube 5 placed on the spindle and a yam running form a drafting unit (not shown) to the traveler on the ring on the ring rail 2 and thereby building a spinning balloon 4. The spinning ballon 4 has a height that extents from the yam guide 3 to the ring rail 2 - the position of the ring rail 2 in this context stands for the heights of the traveler that runs around the ring which is arranged on the ring rail 2.

[0042] In the shown embodiment the spinning unit shows an optional balloon restriction ring 6. In the upper half of Fig. 1 different phases 0.1 - 0.5 of a conventional ring spinning method, a standard setting for carrying out the method so to say, are shown.

[0043] In the lower half the setting according to the different phases 1.1 - 1 .5 of an embodiment according to the invention are shown.

[0044] In the first phase, the initial phase of the cops building process, the position of the yarn guide 3 relative to the tube 5 is set lower in the embodiment according to the invention than in the standard setting.

[0045] According to a standard setting the position of the ring rail 2 is at 10 mm and the yarn guide 3 at a position of ring rail 2 position plus length of the tube 5 plus 37 mm. In an embodiment according to the invention the position of the rig rail 2 is at 10 mm and the yam guide 3 at a position of ring rail 2 position plus length of the tube 5 plus 30 - 32 mm. This lower position of the yam guide 3 results in a smaller spinning balloon height 4, i. e. the height of the balloon 4 built by the yam running between the yam guide 3 and the ring respectively the traveler running on the ring arranged on the ring rail 2, than results in the standard setting.

[0046] As shown in Fig. 1 in a cops building process according to the standard setting / conven- tional method, the yam guide 3 starts to vertically move before it does in the method according to the invention, namely only after completion of 15 - 40 %, preferably 17 - 30 %, even more preferably between 25 - 28 % of the cops building process. The completion in % is defined by the amount of yam that is wound on the tube 5, i. e. how far advanced is the cops building. Or in other words, how many of the three parts of a characteristic cops are built already until the cops is full, i. e. 100% completion of the cops building process. This is schematically shown by the lines A and B connecting the different yam guides in Fig. 1 by leaving the yam guide 3 in the same position until phase 1 .3 whereas the yam guide in a method according to the state of the art starts to move earlier, namely between phase 0.2 and phase 0.3. After the initiation of the vertical movement of the yam guide 3 the yam guide 3 is lifted in a continuous way until the final position in phase 0.5, 1.5 is reached. In this final position the balloon height is the same in both embodiments and allows for doffing without any changes in the setting of the doffer. During the whole process the ring rail 2 with the ring arranged on it is lifted continuously from around 10 to 165 mm while moving up and down to build the three parts (base, middle section and tip) of the cops.

[0047] As can be seen in Fig. 1 the method according to the disclosed embodiment of the invention results in a shorter balloon height 4 throughout the whole cops building process, throughout all the phases of the ring spinning method since the movement of the ring respectively the ring rail is the same in standard setting and in a setting according to the invention.

[0048] The shorter balloon reduces the tension in the yarn and thereby reduces the number of yam breakages throughout the whole process but especially at the beginning of the cops building process, where piecing is especially cumbersome.

[0049] Fig. 2 shows a diagram with the axis “Ring rail position” and the axis “Balloon height”, wherein the balloon height is defined as the height the yarn builds during the spinning process, the cops building process between the yarn guide and the ring (in this text this is simplified by referring to the height of the ring rail).

[0050] The diagram shows the different balloon heights at the different ring rail positions during a cops building process. The upper line “standard” refers to the standard setting respectively a standard spinning method while the lower line “new” refers to the settings according to an embodiment of the invention. The comparison of the upper curve with the lower curve shows that the height of the spinning balloon is shorter during the whole spinning process / cops building process and that the ring rail position is changed in the same way in both methods, standard and new.

[0051] Fig. 3 shows an embodiment of a ring rail and yam guide (shaft) gear box 16 comprising the parts a kit for upgrading a ring spinning machine operating according to a standard method to a ring spinning machine operating according to a method according to the invention may comprise. The displayed gear box 16 shows a lifting tape for the yam guide tube 7. Further a pulley 18 of a diameter allowing for carrying the method according to the invention as well as a stopper 11 . The stopper 11 is to be arranged in a way that allows to control the vertical movement of the yam guide, respectively the yam guide shaft to start moving only after completion of 15 - 40 % of the cops building process. Fig. 3 further shows an adapted roller rest 9 for fixing the guiding rollers to guide the lifting tapes for the yam guide 7 as well as for the ring rail 17. A first clamping piece 13 for clamping the lifting tape 7 to the stopper 11 , and a second clamping piece 8 for positioning the lifting tape 7 on a spacer 12 are shown as well as the spacer 12 for achieving the desired ratio of the movement of the ring rail 2 versus the yarn guide shaft, a clamping lug 10 for connecting the lifting tape 7 to the gear box shaft, a cam 14 for activating the ring rail top and bottom safety limit switches and a limit switch bracket 15 for mounting the limit switches.

Claims

Claims1 . Method of operating a ring spinning machine, wherein a yam runs between a nip point of a pair of exit rollers of a drafting system, through at least one vertically moveable yarn guide 3 and a traveler which runs on a ring being arranged on a vertically movable ring rail 2 , and is twisted, and for cops building wound on a tube 5 having a length which is placed on a spindle, wherein during cops building between the ring rail 2 and the yarn guide 3 a spinning balloon 4 with a height is built; and wherein at least the ring rail 2 is vertically moved relative to the yarn guide whereby the height of the spinning balloon 4 is determined and wherein an initial position of the yarn guide 3 is selected in such a way, that the built spinning balloon 4 has a height of 30 - 32 mm plus the length of the tube 5 , and wherein the initial position is kept during the initial phase of the cops building process, especially until the first 15 % - 40 % of the cops building process are completed.

2. Method according to claim 1 , wherein after completion of the first 15% - 40% of the cops building process a vertical movement of the yarn guide 3 relative to the ring rail 2 is initiated.

3. Method according to claim 1 , wherein after completion of the first 17 % - 30 % of the cops building process a vertical movement of the yarn guide 3 relative to the ring rail 2 is initiated.

4. Method according to claim 2, wherein the vertical movement of the yam guide 2 relative to the ring rail 2 is initiated after completion of 30 % - 40 % of the cops building process.

5. Method according to any of claims 2 to 3, wherein the relative movement between the ring rail 2 and the yam guide 3 shaft is carried out in a ratio 1 :0.75.

6. Method according to any of claims 2 to 4, wherein during the final cops building process the spinning ballon 4 height reaches 115 - 120 mm, especially 118 mm.

7. Method according to any of the preceding claims, wherein the yarn runs through at least one balloon restricting ring 6.

8. Ring spinning machine adapted to carry out the method according to claims 1 - 7.

9. Kit for retrofitting a ring spinning machine in order to be operable according a method as claimed in claims 1 - 7 comprising at least a lifting tape 7 for the yarn guide shaft.

10. Kit according to claim 9 further comprising a pulley 18 and a stopper 11 . 11 . Kit according to claim 10 further comprising at least one of a clamping piece (8, 13), a roller rest (9), a clamping lug (10), a spacer (12), a cam ring rail (14) and / or a limit switch bracket (15).

Images