Knotless pneumatic splicing method for spinning threads or yarns and equipment for implementing method

Abstract

The invention discloses a knotless pneumatic splicing method of spinning threads or yarns and equipment for implementing the method. The method comprises the following steps: a) inserting two yarns to be spliced into a mixing chamber of knotless pneumatic splicing equipment; b) locking an introduction portion of the two yarns introduced into the mixing chamber; c) cutting the extraction portions of the two yarns extracted from the mixing chamber; d) retracting the cut tails of the two yarns into the mixing chamber in the insertion direction, the cut tails overlapping each other by a predetermined overlap length; e) performing a first pneumatic splicing of the overlapping yarn tails by injecting compressed air into the mixing chamber; fi) moving the spliced yarn along the chamber by a predetermined i-th segment of the overlap length; and gi) performing an (i + 1)-th pneumatic splicing of the two overlapping yarn tails by injecting compressed air into the mixing chamber, in which the i-th traveling step fi) and the step gi) of performing the (i + 1)-th splicing are repeated i times, the index i varying from 1 to n; and h) releasing the blocking part of the two spliced yarns.

Description

Technical Field

[0001] The invention relates to a knotless pneumatic splicing method for textile threads or yarns and equipment for implementing the method. Background Art

[0002] Knotless pneumatic splicing devices for textile threads or yarns are already known, which use compressed air both as a means of preparing (untwisting, opening and parallelizing) the yarn ends to be spliced ​​and as a splicing element for mixing the prepared end fibers.

[0003] In a known manner, such an apparatus comprises a mixing chamber provided with a longitudinal slit for introducing the ends of the threads or yarns to be spliced, and holes or nozzles for injecting jets of compressed air therein. At the axially opposite ends of the mixing chamber, there are provided locking clamps for locking the introduction portions of the two yarns introduced into the mixing chamber, scissors for cutting the lead-out portions of the two yarns led out of the mixing chamber, a preparation device (duct and nozzle) in which the cut ends of the two yarns are untwisted and opened by compressed air, and a retraction rod suitable for intercepting the introduction portions of the two yarns introduced into the mixing chamber, for retracting their respective untwisted cut ends from the preparation device in the insertion direction into the mixing chamber and overlapping them by a predetermined overlap length. In addition, a cover or chamber cover for closing the longitudinal slit of the mixing chamber, as well as a plate for guiding the yarns, can also be provided.

[0004] In this device, yarns are twisted by performing the following steps: guiding the yarns to be twisted into a mixing chamber through its longitudinal slit; locking the introduction parts of the two yarns introduced into the mixing chamber; cutting the lead-out parts of the two yarns led out of the mixing chamber; pneumatically preparing (untwisting and opening) the tails of the two yarns to be cut; retracting the cut and prepared tails in the insertion direction and overlapping them into the mixing chamber; injecting compressed air into the mixing chamber to obtain the twisting of the two yarns; and opening all the mechanisms of the device to release the yarns thus twisted.

[0005] In certain applications, multiple splices are made between two yarns, for example to obtain a spliced ​​yarn of the desired mechanical strength. This is necessary, for example, in situations where single continuous or discontinuous long yarns, aramid, industrial and technical yarns need to be spliced.

[0006] For this purpose, a known method is to arrange in succession a corresponding plurality of splicing devices or mixing chambers, each of which is driven to obtain a corresponding splicing point along a corresponding portion of the two yarns.

[0007] However, such solutions are difficult to construct and operate, requiring multiple devices or mixing chambers for each yarn, whose operability needs to be debugged, whose drives need to be coordinated and which require maintenance.

[0008] Furthermore, this solution has a non-negligible size and weight.

[0009] Providing a plurality of devices or mixing chambers connected in series requires a corresponding plurality of commissioning systems which may differ from one another.

[0010] Furthermore, the number and position of the splicing points are fixed by the number of mixing chambers present, their size and their relative position, and these data cannot be changed unless the entire splicing system is modified.

[0011] Furthermore, this known solution has high installation, maintenance and management costs, requiring the arrangement of several devices and mixing chambers for each yarn to be processed. Summary of the invention

[0012] An object of the present invention is to provide an alternative method for knotless pneumatic splicing of textile threads or yarns, and a device for implementing the method, which overcomes the disadvantages of the prior art.

[0013] An object of the present invention is to provide an alternative method for knotless pneumatic splicing of textile threads or yarns which allows to obtain multiple splicing points of the same yarn more easily and quickly.

[0014] One object of the present invention is to provide an alternative method for knotless pneumatic splicing of textile threads or yarns which simplifies the facilities required for its implementation and allows reducing its installation, management and maintenance costs.

[0015] An object of the present invention is to provide an alternative method for knotless pneumatic splicing of textile threads or yarns, and a device for implementing this method, which allows obtaining multiple splicing points of the same yarn with good quality both in terms of appearance and mechanical properties, thereby allowing improved control of the splicing parameters.

[0016] Another object is to allow multiple splices to be made in any number and position, independent of the number of mixing chambers present, their size and their relative position.

[0017] These objects are achieved according to the invention by a method for knotless pneumatic splicing of textile threads or yarns and a device for carrying out the method as set forth in the independent claims.

[0018] Further features are provided in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The characteristics and advantages of the method for knotless pneumatic splicing of textile threads or yarns according to the invention and of the device for implementing the method will become more apparent from the following exemplary and non-limiting description with reference to the attached schematic drawings, in which:

[0020] Figures 1 to 11 Schematically shows a plan view of a device for realizing knotless pneumatic splicing in different states, which are used to realize various steps of a possible embodiment of the splicing method according to the present invention;

[0021] Fig. 12A and 12B Schematically shows a plan view of a device for achieving knotless pneumatic splicing in different states, which are used to implement possible optional steps of the splicing method according to the present invention;

[0022] Figures 13 to 21 Schematically shows a plan view of a device for achieving knotless pneumatic splicing in different states, which are used to implement various steps of a possible alternative embodiment of the splicing method according to the present invention;

[0023] Fig. 22 Schematically shows a plan view of a device for achieving knotless pneumatic splicing in a state for implementing possible further optional steps of the splicing method according to the present invention;

[0024] Fig.23 is a block diagram schematically showing the steps of the twisting method according to the present invention;

[0025] Fig.24 and Fig.25 is a block diagram of two possible embodiments of the steps of the i-th movement and subsequent splicing of the splicing method according to the present invention;

[0026] Fig.26 , 27 28 schematically show different possible embodiments of a knotless pneumatic splicing device for implementing the method according to the invention. DETAILED DESCRIPTION

[0027] With reference to the accompanying drawings, a device 10 for knotless pneumatic splicing is schematically shown for illustrative and non-limiting purposes, for implementing the method for knotless pneumatic splicing of two textile threads or yarns according to the present invention. It can be clearly seen from the following description that the method according to the present invention implements the pneumatic splicing of two threads or yarns through multiple splicing points (i.e., through a series of two or more splicing points obtained at different points of the overlapping length of the end portions (tails) of the two threads or yarns), so the method can be called a multiple splicing method or a multiple blowing method.

[0028] In the following description, two yarns are twisted together as an example, and the two yarns are a first yarn A and a second yarn B respectively.

[0029] For example, by way of example only, a first yarn A may come from a spool S or other source, while a second yarn B may come from a reel R or other source.

[0030] The device 10 comprises a mixing chamber 11 which is open at axially opposite ends and is arranged on top of a longitudinal slit through which two yarns to be spliced, namely a first yarn A and a second yarn B, can be inserted.

[0031] The mixing chamber 11 is provided with holes or nozzles 11a (shown only schematically) through which one or more jets of compressed air are supplied thereto by means of means (not shown) of a known type for supplying compressed air.

[0032] A cover or chamber cover (not shown, of known type) may be provided, suitable for closing the longitudinal slit of the mixing chamber 11 after the two yarns to be spliced ​​are inserted therein. Then, a possible plate or screen (also not shown, of known type) may be provided, suitable for at least partially overlapping the openings at the axially opposite ends of the mixing chamber 11 and / or intervening with the two yarns to be spliced ​​introduced therein (for example, to retain them during one or more steps of the splicing method).

[0033] The device 10 also includes at least the following mechanisms:

[0034] a pair of locking clamps 12, 13 for locking the introduced portions of the two yarns to be spliced ​​introduced into the mixing chamber 11, wherein each of the two locking clamps 12, 13 is movable between at least one open position, in which it keeps the passage of the corresponding yarn portion unobstructed, and a closed position, in which it clamps the corresponding yarn portion to block it;

[0035] a pair of scissors 14, 15 for cutting the lead-out portions of the two yarns led out of the mixing chamber 11, wherein each of the two scissors 14, 15 is movable between at least one open position, in which it does not interfere with the corresponding yarn portion, and a closed position, in which it interferes with the corresponding yarn portion by cutting;

[0036] At least one pair of interception bars 16, 17 for intercepting the introduction portion of the two yarns introduced into the mixing chamber 11, wherein each such interception bar 16, 17 is arranged downstream of the corresponding locking clamp 12, 13 and can be moved between at least one static position in which it does not intercept the corresponding yarn portion and at least one working position in which it intercepts the corresponding yarn portion. More precisely, the interception bars 16, 17 can be moved substantially continuously to a plurality of different working positions.

[0037] For the purpose of clarity of description only and without any limiting purpose, the adjective "first" will be used hereinafter to refer to the clamps, scissors, intercepting bars and other mechanisms described below, which are configured and arranged to act on the first yarn A, and the adjective "second" will be used to refer to the clamps, scissors, intercepting bars and other mechanisms described below, which are configured and arranged to act on the second yarn B.

[0038] At a certain distance from the axially opposite ends of the mixing chamber 11, there can be two inlet 18, 19 and outlet 20, 21 separators and / or guides for yarns A and B, namely the first inlet guide 18 and the first outlet guide 20 of the first yarn A and the second inlet guide 19 and the second outlet guide 21 of the second yarn B.

[0039] The device 10 also includes a pair of retraction rods, which are configured to act on the introduction parts of the two yarns introduced into the mixing chamber 11, for retracting them into the mixing chamber 11 along the insertion direction, wherein each retraction rod moves between at least one static position and at least one working position, in which the static position it does not intercept the corresponding yarn part, and in which working position it intercepts the corresponding yarn part.

[0040] As shown in the drawings, the retraction rod preferably coincides with the interception rod 16, 17, i.e. the retraction rod also consists of the interception rod 16, 17. Therefore, in the following, the expression interception and retraction rod 16, 17 will also be used.

[0041] As is known, in use, the device 10 cooperates with two gripping mechanisms of the yarns to be spliced, which gripping mechanisms may comprise, for example, a first suction opening 300 and a second suction opening 400 .

[0042] like Figure 1 As shown, the first yarn A to be twisted from the bobbin S and held by the first suction port 300 is guided into the mixing chamber 11 through the corresponding first locking clamp 12 in the corresponding open position, and is led out from the axial end of the mixing chamber 11 opposite to the axial end where the first locking clamp 12 is arranged through the corresponding first scissors 14 in the open position.

[0043] Similarly, the second yarn B to be twisted from the reel R and held by the second suction port 400 is guided into the mixing chamber 11 through the corresponding second locking clamp 13 in the corresponding open position, and is led out from the axial end of the mixing chamber 11 opposite to the axial end where the second locking clamp 13 is arranged through the corresponding second scissors 15 in the open position.

[0044] Thus, each of the two yarns has an introduction portion (indicated by A' and B', respectively) introduced into the mixing chamber 11 and a withdrawal portion (indicated by A" and B", respectively) withdrawn from the mixing chamber 11.

[0045] The lead-in portion is intended to mean a portion of the first yarn A and the second yarn B, respectively, which extends from one side of the respective source (spool S or reel R) to between the respective locking clamp 12 , 13 and the mixing chamber 11 .

[0046] The lead-out portion is intended to mean a portion of the first yarn A and the second yarn B, respectively, which extends beyond the axial end of the mixing chamber 11 opposite to that at which the respective locking clamp 12, 13 is arranged to reach the respective scissors 14, 15. Expressions such as "downstream" and "upstream" refer to the direction extending from the clamp to the scissors acting on the same yarn of the two yarns to be spliced.

[0047] The device 10 may also include a pair of preparation devices 22, 23, which are configured to pneumatically prepare the cut tails of the two yarns to be twisted to the subsequent twisting point by opening and / or untwisting and / or parallelizing their respective fibers through one or more compressed air jets. The preparation devices 22, 23 are arranged to act on the two yarns drawn out of the mixing chamber 11 as soon as they are cut. They consist of a pipe provided with one or more holes or nozzles for injecting compressed air and are of a known type (and therefore not described in further detail).

[0048] like Fig.23 As shown, the knotless pneumatic splicing method for textile lines or yarns according to the present invention comprises at least the following steps:

[0049] a) inserting two yarns to be spliced ​​(respectively a first yarn A and a second yarn B) into a mixing chamber 11 of a device 10 for knotless pneumatic splicing (step 100);

[0050] b) respectively locking the introduction portions of the two yarns introduced into the mixing chamber 11, namely the introduction portion A' of the first yarn A and the introduction portion B' of the second yarn B (step 101);

[0051] c) cutting the lead-out portions of the two yarns led out from the mixing chamber 11, namely the lead-out portion A" of the first yarn A and the lead-out portion B of the second yarn B respectively (step 102);

[0052] d) retracting the cut tails of the two yarns respectively, the tails consisting of the lead-out portion A" of the first yarn A and the lead-out portion B" of the second yarn B, wherein the first yarn A and the second yarn B remain unchanged along the direction in which they are inserted into the mixing chamber 11 after cutting, wherein the cut tails of the two yarns overlap each other by a predetermined overlap length (step 103);

[0053] e) performing a first pneumatic splicing G1 on the tails of the two overlapping yarns by injecting compressed air into the mixing chamber 11 (step 104);

[0054] f i ) moving the thus-twisted yarn along the mixing chamber 11 for a predetermined i-th section of the overlap length (step 105); and

[0055] g i ) The i+1th pneumatic splicing G is performed on the tails 106 of the two overlapping yarns by injecting compressed air into the mixing chamber 11. i+1 (Step 106), wherein the swimming step f i ) (step 105) and twisting step g i ) (Step 106) The number of repetitions is equal to i, and the index i changes from 1 to n (in Fig.23 , the repetition of step 105 and step 106 is represented by step 107);

[0056] h) releasing the previously locked portions of the two yarns, ie the introduced portions A', B' of the first yarn A and the second yarn B, respectively (step 108).

[0057] The above steps a) to h) are preferably performed sequentially one after the other.

[0058] The index i is preferably equal to 2 but is not required.

[0059] Still more preferably, but not necessarily, the index i is equal to 2, and:

[0060] When the index i is equal to 1, the i-th walking step 105 occurs along the first direction F1, and

[0061] When the index i is equal to 2, the i-th walking step 105 occurs along a second direction F2 opposite to the first direction F1.

[0062] The index i should be assigned equal to an integer, ranging from 1 to n, where n ≥ 1.

[0063] Although the exemplary and non-limiting case of n=2 is mentioned in the present description, i.e., the case where two yarns A, B are twisted with each other using a total of three (i+1=n+1) twisting points (i.e., the first twisting G1, the second twisting G2, and the third twisting G3), as can be immediately understood by a person skilled in the art, different cases (e.g., n equals 1 (n=1) for a total of two twistings, or n>2 for more than three twistings) are also feasible. The total number of twistings (equal to i+1, where i varies from 1 to n) will depend, for example, on the design choices derived from the nature and type of the yarns to be twisted, the overlapping length of the corresponding tails, the twisting characteristics to be obtained, the type of mixing chamber adopted, etc.

[0064] Furthermore, in this specification, the following situation will be mentioned in an exemplary and non-restrictive manner: the three twists G1, G2 and G3 are arranged at intervals from each other along a section of the overlapping length of the tails of the two yarns A and B, wherein in particular the second twist G2 and the third twist G3 are arranged symmetrically with respect to the first twist G1. However, as can be immediately understood by those skilled in the art, in different situations, the twist points after the first twist point are arranged in different ways (equally spaced or unequally spaced from each other) along the overlapping length of the two yarn tails on one side and / or both sides relative to the first twist G1.

[0065] Generally speaking, when the index i is equal to or greater than 2 (i≥2), the lengths of the i running segments can be equal to or different from each other, and obtained in the same direction or in opposite directions.

[0066] A step 109 of increasing the length of the introduction portions of the two yarns A and B introduced into the mixing chamber 11 (i.e., the introduction portion A' of the first yarn A and the introduction portion B' of the second yarn B), respectively, may be provided preferably before the cutting step 102. Such a step 109 is optional and allows increasing the length of the portion of the two yarns that can overlap each other, thereby increasing the time required for performing a plurality of splices G. i+1 The execution of the increasing step 109 which increases the length of the introduction portion of the two yarns introduced into the mixing chamber 11 depends not only on the total number of splices to be performed, but also on the type and nature of the yarns to be spliced. This increasing step 109 can be preferably performed after the locking step 101, but can also be performed before the locking step 101.

[0067] Preferably, after the cutting step 102, a step 110 may be provided for pneumatically preparing the cut ends of the two yarns A, B by injecting compressed air into the corresponding preparation devices, the first and second preparation devices 22, 23, respectively.

[0068] Preferably, before the releasing step 108, a step 111 is provided for moving the twisted yarn along the mixing chamber 11 to restore its position corresponding to performing the first twisting G1.

[0069] It should be noted that the method according to the invention may also include steps of a type not described here but known to a person skilled in the art, depending on the nature and type of the yarn to be spliced ​​and the type of splicing equipment used. Among these steps, there is included closing the lid or chamber cover (if any) after the insertion step 100 and the subsequent opening before and after the release step 108, or injecting a dose of water into the mixing chamber 11 or into the air jet injected therein, or even heating the compressed air injected into the mixing chamber and / or the preparation device 22, 23, or even moving the yarn during the preparation step, and these are just a few examples.

[0070] According to a first possible embodiment of the method of the present invention, Fig.24 As shown, the i-th swimming step 105 of swimming the twisted yarn includes the following steps:

[0071] Keeping the introduction portions of the two yarns introduced into the mixing chamber 11 locked simultaneously (step 150);

[0072] The introduction portions of the two yarns introduced into the mixing chamber 11 are moved downstream of their locking points, thereby increasing the length of one of the two introduction portions and shortening the length of the other portion (step 151).

[0073] According to a second possible embodiment of the method of the present invention, Fig.25 As shown, the i-th swimming step 105 of swimming the twisted yarn includes the following steps:

[0074] Release one of the two introduction parts of the two yarns introduced into the mixing chamber 11, and keep the other introduction part locked (step 152);

[0075] The introduction portions of the two yarns introduced into the mixing chamber 11 are moved downstream of their locking point, thereby increasing their both lengths (step 153).

[0076] After moving step 153, the following optional steps may be provided:

[0077] The previously released one of the two introduction portions of the two yarns introduced into the mixing chamber 11 is locked again (step 154).

[0078] This locking step 154 ​​is optional and its omission allows the splicing cycle to be accelerated, whether it is performed depends on the number of splices to be made after the first splice, the position where these splices must be made, the position of the interception and retraction rods 16, 17, the type and properties of the yarn and the mixing chamber 11.

[0079] It should be noted that the "locking point" refers to the position where the introduction portion of the two yarns A and B can be clamped by the corresponding locking clamps 12 and 13, regardless of whether the locking clamps 12 and 13 are open or closed. Therefore, the "locking point" is defined by the position of the locking clamps 12 and 13.

[0080] In the above two embodiments, when the index i is equal to or greater than 2 (i≥2), the movement steps 151, 153 of moving the introduction parts of the two yarns introduced into the mixing chamber 11 to downstream of their locking points after the first twisting can occur in the same direction or in the opposite direction to the direction of the first twisting, and the length is equal to or different from the length of the first twisting.

[0081] Now refer to Figures 1 to 11 , a possible embodiment of the method according to the invention using the device 10 as described above is described in more detail, wherein for exemplary and non-limiting purposes, the two yarns A, B to be spliced ​​are spliced ​​with a total of three splicing points, wherein the second splicing point and the third splicing point are arranged symmetrically with respect to the first splicing point, and the i-th swimming step 105 is performed by Fig.24 The steps shown are implemented.

[0082] Figure 1 The insertion step 100 of inserting two yarns to be spliced ​​(first yarn A and second yarn B) into the mixing chamber 11 is shown. In this insertion step, the first clamp 12 and the second clamp 13 are in the open position, the first scissors 14 and the second scissors 15 are in the open position, and the first intercepting rod 16 and the second intercepting rod 17 (i.e., the retraction rod) are in the static position.

[0083] Figure 2 A subsequent locking step 101 is shown, which locks the lead-in portions of the two yarns to be spliced ​​introduced into the mixing chamber 11. The lead-in portion A' of the first yarn A is clamped in a closed position by the first clamp 12. The lead-in portion B' of the second yarn B is clamped in a closed position by the second clamp 13. In this step, the first scissors 14 and the second scissors 15 are in an open position, and the first intercepting rod 16 and the second intercepting rod 17 (i.e., the retraction rod) are in a stationary position.

[0084] Figure 3A subsequent cutting step 102 is shown, which cuts the lead-out portions of the two yarns A and B led out from the mixing chamber 11, i.e., the lead-out portions of the two yarns A and B led out from the end of the mixing chamber 11 axially opposite to the end at which the corresponding first clamp 12 and second clamp 13 are arranged. The lead-out end A" of the first yarn A is cut by the first scissors 14 (in the closed position), resulting in a corresponding cut tail. The lead-out end B" of the second yarn B is cut by the second scissors 15 (in the closed position), resulting in a corresponding cut tail. In this step, the first clamp 12 and the second clamp 13 are in the closed position, and the first intercepting rod 16 and the second intercepting rod 17 (i.e., the retraction rod) are in a stationary position.

[0085] Figure 4 A subsequent retraction step 103 of retracting the cut tail in the insertion direction into the mixing chamber 11 is shown. This retraction step is performed with the aid of a retraction rod, which, as mentioned above, also consists of interception rods 16, 17. The first interception and retraction rod 16 and the second interception and retraction rod 17 are respectively movably driven from their static positions to their working positions where they intercept the introduction portion A' of the first yarn A and the introduction portion B' of the second yarn A, so as to retract the corresponding lead-out portion A", B" or better the corresponding cut tail in the insertion direction into the mixing chamber 11, as shown by arrow F. Therefore, the cut tails of the two yarns A, B are placed side by side and overlap a predetermined overlap length, which depends on the movement amplitude of the interception rod 16 and the retraction rod 17 and the useful length of the introduction portion of the two yarns B, A. It should be noted that the two interception and retraction rods 16, 17 move forward symmetrically relative to the corresponding static positions, as shown in the circle details. In this step, the first clamp 12 and the second clamp 13 are in a closed position. In case the apparatus 10 is provided with a lid or chamber cover, closing the lid or chamber cover during the retraction step 103 and / or during the steps of swimming and moving the yarn is optional and depends on the nature and type of yarn and the type of splicing to be obtained.

[0086] Figure 5 A subsequent step 104 of performing the first twisting G1 by injecting compressed air into the mixing chamber 11 is shown. In this step, the first clamp 12 and the second clamp 13 are in the closed position, and the first interception and retraction rod 16 and the second interception and retraction rod 17 are fixed in the working position reached at the end of the previous retraction step 103. At the end of this step, the two yarns A, B are twisted into one yarn by means of the first twisting G1.

[0087] Figure 6The first step (i=1) of the movement step 105 is shown, which moves the already twisted yarn along the mixing chamber 11 to move the first section of the overlapping length of the cut tail. This first movement occurs along a first direction indicated by the arrow F1, which is parallel to the longitudinal extension of the mixing chamber 11. This first movement step 105 will keep the first clamp 12 and the second clamp 13 in the closed position, i.e. keep the two yarn introduction parts A', B' locked ( Fig.24 Step 150), and moving the lead-in sections A', B' to corresponding downstream locking points to increase the length of one lead-in section and shorten the length of the other lead-in section ( Fig.24 Step 151). This movement is obtained by means of the first interception and retraction rod 16 and the second interception and retraction rod 17 that are driven in opposite directions. However, the first interception and retraction rod 16 and the second interception and retraction rod 17 are not necessarily driven to produce displacements of equal magnitude. In the exemplary case, the first interception and retraction rod 16 is driven backward (i.e. in the return direction towards its rest position), while the second interception and retraction rod 17 is driven forward, i.e. in a direction further advanced relative to the working position reached at the end of the retraction step 103. Therefore, the path of the introduction portion B' of the second yarn B is extended, while the path of the introduction portion A' of the first yarn A is shortened, thereby generating a movement F1 of the twisted yarn along the mixing chamber 11 through another first portion of the overlapping length of the tail cut therein. At the end of this step, the first twist G1 can be located inside or outside the mixing chamber 11, depending on the distance over which the various twists must be made, their number, the type and nature of the yarn, and the type of mixing chamber 11 used.

[0088] Figure 7 A subsequent step 106 of performing a second (i+1) twist G2 by injecting compressed air into the mixing chamber 11 is shown. This second twist G2 is performed along a segment of the overlapping length of the cut tail that is different from the segment in which the first twist G1 was performed; the first twist G1 and the second twist G2 are adjacent to each other along the twisted yarn. During this step, the first clamp 12 and the second clamp 13 are in the closed position, and the first interception and retraction rod 16 and the second interception and retraction rod 17 are stationary in the working position they reached at the end of the previous swimming step 105.

[0089] Figure 8The second step (i=2) of the movement step 105 of a second section of the overlapping length of the twisted yarn from the first twist G1 and the second twist G2 along the mixing chamber 11 is shown. Preferably, but not necessarily, this second movement occurs along a second direction indicated by the arrow F2, which is parallel to the longitudinal extension of the mixing chamber 11 and opposite to the first direction F1. This second movement step 105 keeps the first clamp 12 and the second clamp 13 in the closed position, that is, keeps the introduction portions A', B' of the two yarns locked ( Fig.24 Step 150), and move the lead-in sections A', B' to corresponding downstream locking points so as to increase the length of one lead-in section and shorten the length of the other lead-in section ( Fig.24 Step 151). This movement is obtained by means of the first interception and retraction rod 16 and the second interception and retraction rod 17 which are driven to move in opposite ways. However, the first interception and retraction rod 16 and the second interception and retraction rod 17 are not necessarily driven to produce displacements of equal magnitude. In the exemplary case, the first interception and retraction rod 16 is driven forward, i.e. in a direction of advancement relative to its rest position, while the second interception and retraction rod 17 is driven backward, i.e. in a return direction toward its rest position. Therefore, the path of the introduction portion B' of the second yarn B is shortened, while the path of the introduction portion A' of the first yarn A is increased, so as to generate a movement F2 of the twisted yarn along the mixing chamber 11 through another second section of the overlapping length of the cut tail. This second movement occurs in the opposite direction to the first movement ( Figure 6 ), and intercept and retract the movement of the rods 16, 17 and perform the first swimming step 105 ( Figure 6 ) moves in the opposite direction, as shown in the circled detail. At the end of this step, the first twist G1 and / or the second twist G2 can be located inside or outside the mixing chamber 11, depending on the distance over which the various twists must be made, the number of twists, the type and nature of the yarn, and the type of mixing chamber 11 used.

[0090] Fig. 9 A subsequent step 106 of performing a third (i+1) twist G3 by injecting compressed air into the mixing chamber is shown. This third twist G3 is performed along a section of the overlapping length of the cut tail that is different from the section in which the first twist G1 and the second twist G3 are performed; the first twist G1, the second twist G2 and the third twist G3 are adjacent to each other along the twisted yarn. In particular, the second twist G2 and the third twist G3 are arranged symmetrically with respect to the first twist G1. During this step, the first clamp 12 and the second clamp 13 are in a closed position, and the first interception and retraction rod 16 and the second interception and retraction rod 17 are stationary in the working position ( Figure 8 ).

[0091] Fig.10 A possible further optional step of moving step 111 is shown, which moves the spliced ​​yarn along the mixing chamber 11 to restore the position it assumed during the step 104 of performing the first splicing G1. This step consists in driving the interception and retraction rods 16, 17 so that they return to the working position they assumed at the end of the retraction step 103 ( Figure 4 ).

[0092] Fig.11 A release step 108 is shown for releasing the locked portion of two yarns A, B spliced ​​into one yarn by means of three splices G1, G2 and G3. The first clamp 12 and the second clamp 13 are driven in the open position. Thus, the spliced ​​yarn can be freely extracted from the device 10.

[0093] Fig. 12A A possible optional step 109 of increasing the length of the lead-in portions A', B' of the two yarns A, B to be spliced ​​is shown. This step is performed before the cutting step 102. This step is implemented in a symmetrical manner to drive the interception and retraction rods 16, 17, i.e. both advance from their respective rest positions to their respective working positions where they intercept the respective lead-in portions A', B' of the first yarn A and the second yarn B, thereby increasing the length of the subsequent path. This allows increasing the length by which the first yarn A and the second yarn B can overlap each other, thereby increasing the overlap length that can be used to perform one or more splices after the first splice.

[0094] Fig. 12B The cutting step 102 is shown, assuming that it is in the optional step 109 of increasing the length of the lead-in portions A', B' of the two yarns A, B to be spliced ​​(eg Fig. 12A In this case, the first interception and retraction rod 16 and the second interception and retraction rod 17 are respectively stationary at the working position reached at the end of the previous optional step 109 to increase the length of the introduction portion A', B' of the two yarns A, B to be twisted.

[0095] Fig. 22 The optional step 110 of pneumatically preparing the cut tail by sucking the cut tail into a preparation device 22, 23 into which one or more jets of compressed air are injected is schematically shown.

[0096] It should be noted that when executing each movement step 105 of the moving twisted yarn, as well as the step 103 of retracting the cut tail and the possible step 109 of increasing the introduction part of the two yarns, the two intercepting and retracting rods 16, 17 do not necessarily move the same amount, regardless of whether they are symmetrical movements (forward or backward) or antisymmetrical movements (one forward, one backward).

[0097] Fig.26Schematically shows the implementation according to Fig.23 and Fig.24 A first embodiment of a pneumatic splicing method apparatus 10 is shown.

[0098] The device 10 comprises a respective independent control group 160, 170 for each of the two interception and retraction rods 16, 17. Each independent control group 160, 170 is configured to drive the corresponding interception and retraction rod 16, 17, thereby controlling the drive, movement direction and range independently of the drive of the other interception and retraction rod 16, 17, and driving other mechanisms constituting the device 10 (such as locking clamps 12, 13, scissors 13, 14 and possible lids or chamber covers). The control mechanisms of these further components are generally indicated by reference numeral 600.

[0099] Each independent control group 160, 170 can be electric, pneumatic, or a combination of electric and pneumatic.

[0100] Preferably, each independent control group 160, 170 comprises its own motor mechanism, which is coupled directly or through the interposition of a mechanical transmission to the corresponding interception and retraction rod 16, 17. Such a motor mechanism is preferably constituted by an electronically controllable stepper motor.

[0101] The device 10 is also configured to be connected, in use, to an electronic processing and control unit 500 which can be programmed to implement the splicing method according to the invention and to be connected, in use, to each individual control group 160 , 170 and to the control mechanism 600 .

[0102] Now refer to Figures 13 to 21 , further describing other possible embodiments of the method according to the present invention, wherein for illustrative and non-limiting purposes, two yarns A and B to be spliced ​​are spliced ​​together with a total of three splices, wherein the second splice and the third splice are arranged symmetrically with respect to the first splice, and the i-th swimming step 105 is performed by Fig.25 Since steps 100 to 104 are Figures 1 to 5 The steps shown in Fig. 12A and Fig. 12B as well as Fig. 22 The present invention is the same as all the optional steps mentioned in the present invention, so only the steps and aspects that distinguish the further embodiments of this twisting method from the previously described embodiments are illustrated and described below.

[0103] Fig.13 , 14 15 show steps in which the first step (i=1) of the moving step 105 of moving the yarn twisted by the first twist G1 is performed.

[0104] Fig.13 A release step 152 is shown which releases the introduction portion A' of the first yarn A, keeping locked the introduction portion B' of the second yarn B. The first clamp 12 is driven to the open position, while the second clamp 13 remains in the closed position.

[0105] Fig.14 A subsequent movement step 153 is shown for moving the lead-in portions A', B' of the two yarns A, B already spliced ​​by the first twist G1 downstream of their locking point to increase the length of both of them. This movement produces a first movement of the mixing chamber 11 along the spliced ​​yarns, which moves the first segment of the overlapping length of the cut ends of the two yarns A, B. The first interception and retraction rod 16 and the second interception and retraction rod 17 are driven so that each interception and retraction rod moves forward by a displacement relative to the working position reached at the end of the retraction step 103 (see circled details). As a result, the path length of the lead-in portions A', B' is increased, thereby producing a simultaneous first movement of the spliced ​​yarns from the first twist G1. This first movement occurs along a first direction F1, which extends parallel to the longitudinal extension of the mixing chamber 11 in a direction away from the first clamp 12 (i.e., in the open position).

[0106] Fig.15 The locking prior step 152 ( Fig.13 ) is locked in a locking step 154 ​​of the introduced portion of the yarn released in the first yarn A. Thus, in this case, the first clamp 12 is driven to the closed position so as to lock the introduced portion A' (see circled details) of the first yarn A previously released. As mentioned above, such steps are optional.

[0107] In the first swimming step 105 ( Fig.13 , 14 , 15), at the end, the first twist G1 can be located inside or outside the mixing chamber 11, depending on the distance over which subsequent twisting must be carried out, the number of subsequent twistings, the useful overlap length, the type and properties of the yarn and the type of mixing chamber 11.

[0108] Fig.16 The following step 106 of performing the i+1 splice G2 by injecting one or more compressed air jets into the mixing chamber 11 is shown. In such a step, the first clamp 12 and the second clamp 13 are in a closed position, and the interception and retraction rods 16, 17 are stationary in the first (i=1) swimming step 105 ( Fig.15 ) at the assumed position at the end.

[0109] Fig.17 , 1819 show steps in which a second movement step 105 (i=2) of the yarn twisted via the first twist G1 and the second twist G2 is performed, which is a prerequisite for the subsequent step of performing the third (i+1) twist G3.

[0110] Fig.17 A release step 152 is shown which releases the introduction portion B' of the second yarn B, keeping locked the introduction portion A' of the first yarn A. The second clamp 13 is driven to the open position, while the first clamp 12 remains in the closed position.

[0111] Fig.18 A subsequent movement step 153 is shown for moving the lead-in portions A', B' of the two yarns A, B, which have been spliced ​​by the first splice G1 and the second splice G2, downstream of their locking point to increase their lengths. This movement produces a second movement along the mixing chamber 11, causing the spliced ​​yarn to move a second section of the cut-end overlap length of the two yarns A, B. The first interception and retraction rod 16 and the second interception and retraction rod 17 are driven so that each interception and retraction rod moves another forward displacement relative to the working position reached at the end of the previous first movement step 105 (see Fig.18 Circle the details in Fig.14 ). As a result, the path length followed by the introduction portions A', B' increases, thereby generating a simultaneous second movement of the twisted yarn from the first twist G1 and the second twist G2. This second movement occurs along a second direction F2, which extends parallel to the longitudinal extension of the mixing chamber 11 in a direction away from the second clamp 13 (i.e., in the open position). The second direction F2 is opposite to the first direction F1. However, as previously mentioned, the second movement can occur in the same direction as the first movement, in which case it will be immediately understood by those skilled in the art that the first clamp 12 should be driven in the open position, keeping the second clamp 13 in the closed position.

[0112] Fig.19 The locking prior step 152 ( Fig.17 ) is locked in step 154 ​​of the introduction portion of the yarn released in the second clamp 13. Therefore, in this case, the second clamp 13 is driven to the closed position so as to lock the introduction portion B' (see circled details) of the second yarn B previously released. As mentioned above, such steps are optional.

[0113] In the second swimming step 105 ( Fig.17 , 18and 19), depending on the distance over which subsequent splicing must be performed, the number of subsequent splicings, the useful overlap length, the type and properties of the yarn and the type of mixing chamber 11, the first splice G1 and / or the second splice G2 can be located inside or outside the mixing chamber 11.

[0114] Fig. 20 A subsequent step 106 of performing a third (i+1) splice G3 by injecting one or more jets of compressed air into the mixing chamber 11 is shown. In such a step, the first clamp 12 and the second clamp 13 are in a closed position, while the interception and retraction bars 16, 17 are stationary in the position assumed at the end of the second (i=2) step of the swimming step 105 ( Fig.18 ).

[0115] Fig.21 The subsequent release step 108 of releasing the introduced portion of the two yarns A, B spliced ​​to each other by means of the three splices G1, G2 and G3 is shown. The first clamp 12 and the second clamp 13 are driven to the open position and the spliced ​​yarns can be freely taken out of the device 10.

[0116] Fig. 27 Schematically shows the method for implementing Fig.23 and Fig.25 A second embodiment of the pneumatic splicing method apparatus 10 is shown.

[0117] The device 10 comprises a respective independent control group 120, 130 for each of the two locking clamps 12, 13. Each independent control group 120, 130 is configured to drive the respective locking clamp 12, 13, to control the drive to the open position and the closed position independently of the drive of the other locking clamp 12, 13, and to drive other mechanisms constituting the device 10, such as the interception and retraction rods 16, 17, possible lids or chamber covers, which can be driven by a common control mechanism 700 dedicated thereto. The control mechanisms of these further components are indicated as a whole by the reference numeral 600. The scissors 14, 15 and the clamps can be driven by the same control group 120, 130 (often intervening after the clamps are driven), but also by different control groups.

[0118] Each independent control group 120, 130 can be electric, pneumatic, or a combination of electric and pneumatic.

[0119] Preferably, each independent control group 120, 130 comprises its own motor mechanism, which is coupled directly or through the interposition of a mechanical transmission to the corresponding clamp 12, 13. Such a motor mechanism is preferably composed of an electronically controllable stepper motor.

[0120] The device 10 is also configured to be connected, in use, to an electronic processing and control unit 500 programmed to implement the splicing method according to the invention and to each individual control group 120 , 130 and control mechanism 600 , 700 .

[0121] like Fig.28 As shown, the device 10 for implementing the method of the present invention may also include independent control groups 160, 170 for the two intercepting and retracting levers 16, 17 and independent control groups 120, 130 for the two locking clamps 12, 13, all of which are controlled by an electronic unit 500 during use, and the electronic unit 500 can be programmed to implement the twisting method according to the present invention and is connected to each independent control group 120, 130 and 160, 170 and the control mechanism 600 of the remaining components (scissors, cover) during use.

[0122] In this case, each i-th movement step 105 is performed by combining independent driving of the intercepting bars 16, 17 and the locking clamps 12, 13, and / or the overlapping length of the cut tails that facilitate multiple splicing can be increased.

[0123] The splicing method according to the present invention allows multiple splices between two threads or yarns to be spliced ​​to be easily and accurately obtained in a short time by using a single splicing device.

[0124] Similarly, the splicing device according to the present invention allows multiple splices to be easily made between two threads or yarns in a short time.

[0125] The splicing method according to the invention can be used for splicing any type of thread or yarn. In particular, good splicing effects have been found in the multi-point splicing of aramid and industrial single continuous burr yarns (titration range from medium fine to medium coarse (e.g. 200 dtex ÷ 8000 dtex)).

[0126] The method for splicing according to the invention allows better control of the splicing parameters, thereby obtaining splicing points with greater overall strength. In addition, it allows the number and distance of splicing points to be easily changed without having to change the structure of the equipment implementing these splices.

[0127] The method and device thus conceived are susceptible to numerous modifications and variations, all of which fall within the invention; moreover, all the details may be replaced by technically equivalent elements. In practice, the materials used, as well as the dimensions, may be any, according to the technical requirements.

Claims

1. A method for knotless pneumatic splicing of textile threads or yarns, comprising at least the following steps: a) inserting two yarns (A, B) to be spliced ​​into a mixing chamber (11) of a device (10) for knotless pneumatic splicing (insertion step 100); b) locking the introduced portions (A', B') of the two yarns introduced into the mixing chamber (11) (locking step 101); c) cutting the lead-out portions (A", B") of the two yarns led out from the mixing chamber (11) (cutting step 102); d) retracting the cut ends of the two yarns along the insertion direction into the mixing chamber (11), wherein the cut ends overlap each other by a predetermined overlap length (retracting step 103); e) performing a first pneumatic splicing (G1) on the tails of the two overlapping yarns by injecting compressed air into the mixing chamber (11) (performing step 104); f i ) moving the thus-twisted yarn along the mixing chamber (11) for a predetermined i-th section of the overlapping length (movement step 105); and g i ) performing the (i+1) pneumatic splicing of the tails of the two overlapping yarns by injecting compressed air into the mixing chamber (11) (step 106); The step f of the i-th movement i ) and performing the step g of the i+1th twisting i ) is repeated i times, and the index i can change from 1 to n; h) releasing the blocked portions of the two yarns thus twisted together (releasing step 108).

2. The method according to claim 1, wherein the index i is equal to 2, and when the index i is equal to 1, the swimming step (105) occurs along a first direction (F1), and when the index i is equal to 2, the swimming step (105) occurs along a second direction (F2) that is the same as or opposite to the first direction (F1).

3. The method according to claim 1 or 2, wherein the index i is equal to or greater than 2, and the lengths of the i running segments are equal to or different from each other.

4. The method according to one or more of the preceding claims, comprising, before said cutting step (102), a step (step 109) of increasing the length of the introduced portions (A', B') of said two yarns introduced into said mixing chamber (11).

5. The method according to one or more of the preceding claims, comprising, after the cutting step (102), a step (step 110) of pneumatically preparing the cut ends of the two yarns by injecting compressed air into the respective preparation devices (22, 23).

6. The method according to one or more of the preceding claims, comprising, before said releasing step (108), a step (111) of moving the twisted yarn along the mixing chamber (11) to restore its position corresponding to performing said first twisting (G1).

7. The method according to one or more of the preceding claims, wherein said i-th step (step 105) of moving said twisted yarns comprises the following steps: The two yarn introduction portions (A', B') introduced into the mixing chamber (11) are moved to a downstream locking point, the length of one of the two introduction portions is increased and the length of the other introduction portion is decreased so that they remain locked (step 150).

8. The method according to one or more of the preceding claims, wherein said i-th step (step 105) of moving said spliced ​​yarns comprises the following steps: releasing one of the two introduction portions (A', B') of the yarn introduced into the mixing chamber (11), keeping the other introduction portion locked (step 152); The introduction portions (A', B') of the two yarns introduced into the mixing chamber (11) are moved downstream of their locking point, thereby increasing both of their lengths.

9. The method according to claim 8, wherein after the step (step 153) of moving the two yarn introduction portions (A', B') introduced into the mixing chamber (11) downstream of their locking point, the following steps are provided: The previously released one of the two introduction portions of the yarn introduced into the mixing chamber (11) is locked again.

10. A method according to any one of claims 7 to 9, wherein each of the steps (151, 153) of moving the introduction portion (A', B') of the two yarns introduced into the mixing chamber (11) downstream of its locking point is achieved by intercepting the introduction portion (A', B') with the aid of an intercepting rod (16, 17) of the device (10).

11. A device (10) for implementing the method for knotless pneumatic splicing of two textile threads or yarns according to one or more of the preceding claims, comprising: a mixing chamber (11) open at two axially opposite ends and provided with a longitudinal slit into which the two textile threads or yarns (A, B) to be spliced ​​can be inserted, and equipped with at least one hole or nozzle (11A) for supplying it with compressed air; a pair of locking clamps (12, 13) for clamping the introduced portions (A', B') of the yarn introduced into the mixing chamber (11), wherein each of the clamps (12, 13) is movable between at least one open position, in which it allows the free passage of the corresponding yarn portion, and at least one closed position, in which it clamps the corresponding yarn portion; a pair of scissors (14, 15) for cutting the lead-out portions (A", B") of the two yarns led out of the mixing chamber (11), wherein each scissor (14, 15) is movable between at least one open position, in which it does not interfere with the corresponding yarn portion, and at least one closed position, in which it interferes with the corresponding yarn portion by cutting it; at least one pair of intercepting bars (16, 17) for intercepting the introduced portions (A', B') of the two yarns introduced into the mixing chamber (11), arranged downstream of the respective locking clamps (12, 13) and movable between at least one static position in which they do not intercept the respective yarn portions and at least one working position in which they intercept the respective yarn portions, wherein the device (10) comprises a respective independent control group (160, 170; 120, 130) for each of the two intercepting bars (16, 17) and / or for each of the two locking clamps (12, 13), and Wherein said device (10) is configured to be connected, in use, to an electronic processing and control unit (500) programmed to implement the method according to one or more of the preceding claims.

12. The device according to claim 11 comprises a pair of retraction rods for retracting the yarn into the mixing chamber (11) along the insertion direction, wherein each of the retraction rods is capable of moving between at least one static position and at least one working position, in which the static position it does not intercept the corresponding yarn, and in which working position it intercepts the corresponding yarn.

13. Device according to claim 11, wherein the intercepting rod (16, 17) is constituted by the retraction rod.

14. Apparatus according to any one of claims 11 to 13, wherein the independent control groups (160, 170; 120, 130) each comprise their own motor mechanism, which are coupled to the respective intercepting rod (16, 17) or the respective locking clamp (12, 13).

15. The apparatus of claim 14, wherein the motor mechanism consists of an electronically controllable stepper motor.

16. Device according to one or more of claims 11 to 15, comprising for each interceptor bar (16, 17) a respective said independent control group (160, 170).

17. Device according to one or more of claims 11 to 16, comprising a respective said independent control group (120, 130) for each locking clamp (12, 13).

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