Method and assembly for cleaning and opening roving tubes in a spinning line

Abstract

A cleaning and opening unit (70) for a spinning line for dirty tubes (12) provided with residual roving portions (R; R1, R2 ) comprises a cleaner pipe (72) and an opening assembly (90) connected to the cleaner pipe (72). The opening assembly (90) comprises an outlet duct (94), a partition (92) permeable to air, and a plurality of primary holes (99) for forcibly introducing the air jets into the outlet duct (94) for disintegrating the roving into fibre flocks and / or roving fractions.

Description

METHOD AND ASSEMBLY FOR CLEANING AND OPENING ROVING TUBES IN A SPINNING LINEDESCRIPTIONTechni cal fi eld

[0001] The present invention belongs to the field of textile machines of a spinning line . In particular, the present invention relates to a unit for cleaning and opening the roving, particularly applicable to an integrated exchange device of a spool and tube transport system between a roving frame and a spinning frame of a spinning line .Pri or art

[0002] As is known, the spools formed at the roving frame , consisting of a tube on which the drafted and twisted roving is wound at the frame , are transported to the spinning frame . At the spinning frame , the spools being processed are hung on a frame , from which the rovings depart for being processed at the spinning frame . When the spools being processed are exhausted, they are replaced by the spools coming from the roving frame .

[0003] The exhausted spools consist of the tube completely devoid of roving ( defined as " empty tube" ) or of the tube provided with some res idual windings of roving ( defined as "dirty tube" ) .

[0004] The dirty tubes are cleaned to obtain empty tubes ;the empty tubes thus obtained and those taken from the spinning frame are returned to the roving frame and here replaced with the spools that have in the meantime been formed, so that the roving frame can proceed with the formation of new spools .

[0005] In some plants , the cleaning of the dirty tubes takes place in a speci fic device , usually called a " cleaner" , which eliminates the residual roving .

[0006] The Applicant has instead devised an integrated device for cleaning the dirty tubes and exchanging the empty tubes with the spools formed at the roving frame . Such a device is illustrated in the International Application WO-A1-2016 / 083944 and in documents EP-A1- 3470561 and EP-A1-3385414 , all in the name of the Applicant . Such an integrated device provides primary suction cleaning means and secondary blowing cleaning means , capable of separating the residual roving portions from the dirty tube , dragging them into an air stream .

[0007] In order to maximise the yield of the spinning line , the residual roving portions dragged by the air stream are opened, collected and reintroduced into the spinning process , for example at the battery machines , or stored, for example in bags or pressed into bales , to then be reintroduced into the process at a later time . The Applicant has , however, noted that such roving portions ,although opened or reduced into short fractions , when reintroduced into the spinning process , are often the cause of defects in the yarn produced, presumably due to the compactness of the fibres and the twisted state in which they are found, as well as being the cause of machine ef ficiency problems , for example in battery machines .

[0008] For this reason, some devices are already known, usually called " flock openers" , capable of sucking the residual roving portions , separating them from the tubes , and defibrating them by traction, so as to obtain fibre flocks which, reintroduced into the spinning process , do not give rise to irregularities and imperfections . An example is described in the Italian utility model patent application M095U000021 .

[0009] The known solutions , however, have proven to be poorly suited to modern spinning processes , characterised by particularly high speeds , especially in the case of highly automated lines that use integrated devices for tube exchange .Obj ect of the inventi on

[0010] The obj ect of the present invention is to implement a unit for cleaning and opening the residual roving on dirty tubes that meets the needs of the sector and at the same time overcomes the drawbacks mentioned withreference to the known art .Bri ef descripti on of the drawings

[0011] The characteristics and advantages of the unit for cleaning and opening the roving according to the present invention will be evident throughout the description reported below, provided by way of example and not limitation, in accordance with the figures of the accompanying drawings , in which :- Figure 1 depicts an example of a portion of a spinning line with an integrated exchange device ;Figure 2 illustrates the exchange device with the cleaning and opening unit according to an embodiment of the present invention;- Figure 3 shows a cleaning and opening unit , according to an embodiment of the present invention;- Figure 4 represents a view of the cleaning and opening unit engaged with a dirty tube ;- Figure 5 is an enlargement of a spindle of the cleaning and opening unit , according to an embodiment of the present invention .Detail ed descripti on of an embodiment

[0012] With reference to the accompanying figures , number 1 denotes overall an example of a portion of a spinning line comprising a can region 2 in which a plurality of cans 4 are housed, each containing a sliver roll , aroving frame 6 adj acent to the can region 2 to be fed therefrom with sliver, and a plurality of spinning frames 8 , for example arranged parallel to one another .

[0013] The roving frame 6 drafts and twists the sliver coming from the cans 4 and winds it onto empty tubes , forming spools 10 to be transported to the spinning frame . For this purpose , the spools 10 are made available to a carriage 20 of the roving frame 6 .

[0014] A transport system of the spinning line comprises a main transport device 22 , usually called "deck" , adapted to pick up the spools 10 from the carriage 20 and to move them in suspension, at a predefined height , generally by means of a main belt 22 ' . The main transport device 22 is also adapted to load the carriage 20 with empty tubes 14 .

[0015] The transport system further comprises a secondary transport device 26 adapted to move the spools 10 towards the spinning frames 8 and dirty tubes 12 ( or sometimes empty) towards the roving frame 6 .

[0016] For example , the secondary transport device 26 is shaped as a closed loop and comprises a track 26 ' having portions 8 ' that run parallel to the spinning frames 8 , without interruption .

[0017] The spinning line 1 comprises an integrated device 50 adapted to cooperate with the main transport device 22 serving the roving frame 6 and with the secondarytransport device 26 serving the spinning frames 8 , to carry out the collection of the dirty tubes 12 from the secondary device 26 and of the spools 10 from the main device 22 , the cleaning of the dirty tubes 12 to obtain empty tubes 14 , the exchange of the spools 10 with the empty tubes 14 , and the release of the spools 10 to the secondary device 26 and of the empty tubes 14 to the main device 22 .

[0018] According to an embodiment , for example illustrated in figure 2 , the integrated device 50 cooperates with a terminal portion 26 ' ' of the track 26 ' of the secondary transport device 26 serving the spinning frames 8 and with a terminal portion 22 ' ' of the transport belt 22 ' of the main transport device 22 serving the roving frame 6 .

[0019] An example of an embodiment of the integrated device 50 is described in International Application W0-A1- 2016 / 083944 of the Applicant , the teaching of which is incorporated herein .

[0020] The integrated device 50 comprises a cleaning and opening unit 70 adapted to operate on a dirty tube 12 to suck from it the residual portions of roving R and to open them ( in technical j argon, " flocking" ) , that is , to defibrate them by traction so as to obtain separate fibre flocks and / or roving fractions .

[0021] The cleaning and opening unit 70 comprises a cleanerpipe 72 which extends predominantly along a vertical central tube axis W; when the cleaner pipe 72 is inserted onto the dirty tube 12 , the central tube axis W is arranged coaxially with the dirty tube 12 or parallel to the tube axis Z of the dirty tube 12 .

[0022] The cleaner pipe 72 comprises a cylindrical tube wall 74 , for example divided into a first wall 74a or lower wall and a second wall 74b or upper wall , superimposed and coaxial with the first wall 74a . The tube wall 74 extends axially between a lower end 741 and an upper end 74u along said central tube axis W .

[0023] The cleaning and opening unit 70 cooperates with air suction means (not shown) operated to create an air suction stream Fa inside the cleaner pipe 72 , from the lower end 741 towards the upper end 74u .

[0024] For example , said air suction means comprise a fan configured to create the air suction stream Fa, operatively connected to the upper end 74u of the tube wall 74 .

[0025] The cleaning and opening unit 70 further comprises an opening assembly 90 , connected to the cleaner pipe 72 , preferably entirely inside the cleaner pipe 72 , near the upper end 74u of the tube wall 74 . The opening assembly 90 is configured to intercept the entire cross-section of the air suction stream passage delimited by the tube wall

[0026] The opening assembly 90 comprises an outlet duct 94 , a partition 92 permeable to air and configured to create a choke for the air suction stream Fa and to channel the roving towards the outlet duct 94 , and a primary duct 96 for blowing air which opens into the outlet duct 94 in an opening zone 97 , for example through a plurality of primary holes 99 or blowing holes .

[0027] Preferably, said primary holes 99 are arranged circumferentially with respect to the central tube axis W, for example organised in one or more rows .

[0028] The cleaning and opening unit 70 cooperates with first air blowing means (not shown) , operatively connected upstream to said primary blowing duct 96 , for example through an air fitting 101 , so as to forcibly introduce a first blowing air stream Fl that is divided into primary air j ets blown from the primary holes 99 into the outlet duct 94 .

[0029] Preferably, the primary holes 99 are configured so that the air j ets are directed upwards .

[0030] According to a preferred embodiment , the partition 92 comprises a partition wall 98 annular with respect to the central tube axis W; preferably, the partition wall 98 converges towards the outlet duct 94 .

[0031] For example , the partition wall 98 converges towardsthe central tube axis W towards the upper end 74u, and is preferably f rustoconical , that is , provided with a larger base 104 and a smaller base 106 .

[0032] The partition wall 98 is also provided with a plurality of suitably cal ibrated openings 100 that cross it and make it permeable to air, while still creating a localised choke for the air suction stream .

[0033] Preferably, the partition wall 98 having a converging configuration towards the outlet duct 94 facilitates the channelling of the roving or the collection of any fibre flocks and / or fractions of roving already detached from the residual roving portions R, Rl , R2 , towards said outlet duct .

[0034] For example , the internal diameter of the tube wall 74 is between 20 and 100 times greater than the diameter of one of said openings 100 . For example , in one embodiment , the diameter of the tube wall is between 70 and 90 millimetres , for instance greater than 80 millimetres , and each opening 100 has a diameter between 1 and 2 millimetres , preferably less than 1 . 5 millimetres .

[0035] Preferably, furthermore , the opening assembly 90 comprises a spindle 102 fixed to the partition 92 , for example at the top of the f rustoconical partition wall 98 ; the spindle 102 is axially crossed by the outlet duct94 , arranged for example coaxially with the f rustoconical partition wall 98 , and by the primary duct 96 , which extends along a direction intersecting the central tube axis W, for example orthogonally .

[0036] The cleaning and opening unit 70 further cooperates with second air blowing means suitable for forcibly blowing into the cleaner pipe a plurality of air j ets , around the tube 12 , preferably orthogonally to the central tube axis W .

[0037] For example , said second air blowing means comprise a lower collar 76 , fixed to the lower end 741 of the tube wall 74 , and an air compressor operatively connected to said lower collar 76 .

[0038] The lower collar 76, for example in the form of a ring, externally comprises at least one air fitting 78 and internal paths that open into a plurality of secondary holes 80 , arranged on the inner lateral surface of the lower collar 76 . Preferably, the secondary holes 80 are configured so that the air j ets are directed radially towards the dirty tube , that is , perpendicularly to the central tube axis W .

[0039] The opening assembly 90 is arranged downstream of the secondary holes 80 .

[0040] According to a preferred embodiment , the cleaning and opening unit 70 comprises a first intermediate collar82a, fixed to the upper end of the first wall 74a , provided with an annular support surface 84 , and a second intermediate collar 82b, fixed to the lower end of the second wall 74b .

[0041] Furthermore , preferably, the larger base 104 is applied between the first intermediate collar 82a and the second intermediate collar 82b, so as to entirely intercept the air passage section delimited by the tube wall 74 , while the smaller base 106 is fixed to the spindle 102 .

[0042] Furthermore , the cleaning and opening unit 70 cooperates with actuation means , for example pneumatic or electric, configured to support and translate the cleaner pipe 72 along the central tube axis W between an upper limit position and a lower limit position .

[0043] For example , said actuation means comprise a pneumatic actuator 110 operatively connected to the tube wall 74 of the cleaner pipe 72 .

[0044] During normal operation of the integrated device 50 , the dirty tube 12 is on board the integrated device 50 and has first residual portions of roving R1 . Furthermore , the dirty tube 12 is usually provided with an attachment zone 12a, to which the initial end of the roving of the spool is fixed . Usually, the attachment zone 12a has second residual portions of roving R2 .

[0045] Preferably, the air suction means are permanently active and produce the air suction stream Fa inside the cleaner pipe 72 .

[0046] In an initial operating configuration of the cleaning and opening unit 70 , the cleaner pipe 72 is in the upper limit position .

[0047] In a downward step, by activation of the actuation means , the cleaner pipe 72 is translated towards the lower limit position, slipping over the dirty tube 12 .

[0048] During the downward step, the first air blowing means are also activated . Once the lower limit position is reached, an upward step is initiated, during which, by activation of the actuation means , the cleaner pipe 72 is translated towards the upper limit position, progressively sliding of f the dirty tube 12 . The air suction means continue remaining active , as do the first air blowing means .

[0049] Furthermore , preferably, starting for example from the lower limit position and for a predefined interval of the upward step, the second air blowing means are activated, which, by the action of the air j ets , contribute to the detachment of the residual portions of roving R, Rl , R2 from the dirty tube 12 , and are particularly ef fective in causing the detachment of the second residual portions of roving R2 from the attachmentzone 12a .

[0050] During operation, the air suction stream Fa and the localised depression generated upstream of the partition 92 direct the residual roving portions R, Rl , R2 upwards , that is , towards the partition 92 itsel f ; furthermore , presumably, the air j ets in the outlet duct 94 generate a further localised depression that sucks the ends of the residual portions R, Rl , R2 into the outlet duct 94 , in which the vigorous action of the air j ets and the depression caused thereby disintegrate the roving into fibre flocks and / or very short roving fractions .

[0051] Innovatively, the cleaning and opening unit according to the present invention meets the needs of the sector, as it allows the reintroduction of fibre flocks or very short roving fractions into the spinning process , and overcomes the drawbacks mentioned, since the cleaning of the dirty tubes is particularly fast and suitable for automated lines .

[0052] Advantageously, furthermore , the cleaning and opening unit according to the invention shows lower compressed air consumption, since the cleaning cycle has a very short duration . For example , some tests carried out by the Applicant have shown that a cleaning cycle , in which the cleaner pipe moves from the upper limit position to the lower limit position and returns to theupper limit position, has an average duration of about 10 seconds, whereas a similar cycle, carried out with known devices, lasts about 25 seconds.

[0053] Since the compressed air is blown only during the cleaning cycle, this also results in lower compressed air consumption and thus in reduced energy consumption.

[0054] It is clear that a person skilled in the art, in order to meet contingent needs, could make modifications to the cleaning and opening unit described above, all falling within the scope of protection as defined by the following claims.

Claims

CLAIMS1. A cleaning and opening assembly (70) for a spinning line for dirty tubes (12) having residual roving portions (R;R1,R2) , comprising- a cleaner pipe (72) extending mainly along a vertical central pipe axis (W) , insertable onto the dirty tube (12) , adapted to be fluidly engaged with air suction means for creating an air suction stream (Fa) therein;- an opening assembly (90) , connected to the cleaner pipe (72) , configured to intercept the entire passage section of the air suction stream through the cleaner pipe (72) and arranged, in an operating configuration in which the cleaner pipe (72) engages the dirty tube (12) , downstream of said dirty tube (12) ; wherein the opening assembly (90) comprises at least one outlet duct (94) through which fiber flakes and / or roving fractions can pass, an air-permeable partition (92) configured to form a choke for the air suction stream (Fa) and convey the roving or fiber flakes and / or roving fractions towards the opening duct (94) , and a plurality of primary holes (99) for forcibly introducing air jets into the outlet duct (94) for braking the roving into fiber flakes and / or roving fractions.

2. A cleaning and opening assembly according to claim 1, wherein the partition (92) comprises an annular partitionwall (98) with respect to the central pipe axis (W) , provided with a plurality of calibrated ports (100) which pass therethrough and make it permeable to air and substantially impermeable to fiber flakes and / or roving fractions .

3. A cleaning and opening assembly according to claim 2, wherein the partition wall (98) converges towards the outlet duct ( 94 ) .

4. A cleaning and opening assembly according to claim 3, wherein the partition wall (98) is f rustoconical towards the outlet duct (94) .

5. A cleaning and opening assembly according to any one of the preceding claims, wherein said primary holes (99) are configured so that the air jets introduced into the opening duct (94) are directed upwards.

6. A cleaning and opening assembly according to any one of the preceding claims, comprising a shank (102) attached to the partition (92) , axially crossed by the outlet duct (94) and provided with said blowing holes (99) which lead into the outlet duct (94) .

7. A cleaning and opening assembly according to any one of the preceding claims when dependent on claim 4, wherein the outlet duct (94) is coaxial to the f rustoconical partition wall (98) .

8. Assembly comprising:- a cleaning and opening unit (70) according to any one of the preceding claims;- air suction means operable to generate the air suction stream within the cleaner pipe (72) .

9. Assembly according to claim 8, wherein the air suction means comprise a fan operatively connected to an upper end (74u) of a pipe wall (74) of the cleaner pipe (72) .

10. Assembly according to claim 8 or 9, comprising air blowing means configured to forcibly blow a plurality of air jets around the dirty tube (12) .

11. Assembly according to claim 10, wherein said air blowing means are configured to blow said air jets orthogonally to the central pipe axis (W) .

12. Assembly according to any one of claims 8 to 11, comprising actuation means configured to support and translationally move the cleaner pipe (72) along the central pipe axis (W) .

13. Apparatus for a spinning line (1) comprising:- an integrated device (50) for taking dirty tubes (12) from a secondary conveyor device (26) and spools (10) from a main conveyor device (22) , exchanging the spools (10) for empty tubes (14) , and releasing the spools (10) to the secondary conveyor device (26) and the empty tubes (14) to the main conveyor device (22) ;- a cleaning and opening assembly (70) according to anyone of claims 1 to 7, for cleaning the dirty tubes (12) and obtaining the empty tubes (14) .

14. A method for cleaning dirty tubes (12) provided with residual roving portions (R;R1,R2) and opening the roving, comprising the following steps:- providing a cleaning and opening unit (70) according to any one of claims 1 to 7;- in a cleaner pipe (72) inserted onto the dirty tube (12) , causing an air suction stream (Fa) ;- through the air-permeable partition (92) configured to retain fiber flakes and / or roving fractions, causing a choke of the air suction stream (Fa) downstream of the dirty tube ( 12 ) ; channeling ends of the residual roving portions (R;R1,R2) into the outlet duct (94) downstream of the choke of the air suction stream;- forcibly introducing primary air jets into the outlet duct ( 94 ) ; thus, causing the roving to open, i.e., the breakage into fiber flakes and / or roving fractions.

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