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EP-4328162-B1 - YARN SPLICER DEVICE WITH IMPROVED TAIL TEARING MEANS AND THE RELATED OPERATING METHOD

EP4328162B1EP 4328162 B1EP4328162 B1EP 4328162B1EP-4328162-B1

Inventors

  • BERTOLO, Ivan
  • Floriduz, Moreno
  • PIGHIN, Roberto

Dates

Publication Date
20260506
Application Date
20230803

Claims (15)

  1. Yarn splicer device (4) comprising - a pair of opposite plates (8,12) which are rotatable with respect to a common drive axis (X-X), - the plates (8,12) being spaced apart from each other, along said drive axis (X-X), so as to identify a passage path (14) of a first yarn (16) ending with a first thread (20) and a second yarn (24) ending with a second thread (28), to be mutually spliced, - tail tearing means (32), configured to grasp and tear tails (36) of said first and second thread (20,28), so as to obtain tearing points (40) positioned at least partially inside said passage path (14) of the first and second yarn (16,24), - wherein said tail tearing means (32) comprise a first pair of counter-rotating rotatable cylinders (44), configured to clamp the tail (36) of said first thread (20) and/or a second pair of counter-rotating rotatable cylinders (48), configured to clamp the tail (36) of said second thread (28).
  2. Yarn splicer device (4) according to claim 1, wherein the cylinders of said first pair of rotatable cylinders (44) and/or of said second pair of rotatable cylinders (48) are rotatably supported about rotation axes (Y-Y) parallel to said drive axis (X-X) of the opposite plates (8, 12) .
  3. Yarn splicer device (4) according to claim 1 or 2, wherein said first and second pair of rotatable cylinders (44,48) are arranged in diametrically opposite positions with respect to the drive axis (X-X) of the plates (8,12).
  4. Yarn splicer device (4) according to claim 1, 2 or 3, wherein said first and second pair of rotatable cylinders (44,48) are arranged externally with respect to the plates (8,12) and the passage path (14) of said first yarn (16) and second yarn (24).
  5. Yarn splicer device (4) according to any one of claims 1 to 4, wherein said pairs of rotatable cylinders (44,48) comprise a motor cylinder (60) and an idle cylinder (64) driven by the motor cylinder (60).
  6. Yarn splicer device (4) according to claim 5, wherein each motor cylinder (60) is controlled by a dedicated motor.
  7. Yarn splicer device (4) according to claim 6, wherein said dedicated motor is a stepper electric motor.
  8. Yarn splicer device (4) according to any one of claims 1 to 7, wherein at least one of said cylinders (60,64) of the first and/or second pair of rotatable cylinders (44,48) has a rubbery material surface coating and/or a knurling surface treatment and/or a roughening surface treatment, in order to increase the gripping force on the tails (36) of said threads (20,28).
  9. Yarn splicer device (4) according to any one of claims 1 to 8, wherein the cylinders (60,64) of each pair of rotatable cylinders (44,48) are at least partially in contact with each other so as to obtain a mutual contact pressure and drag the driven idle cylinder (64) by friction.
  10. Yarn splicer device (4) according to claim 9, wherein means are included for adjusting said mutual contact pressure between the cylinders (60,64) of at least one of said pairs of rotatable cylinders (44,48).
  11. Tearing and splicing method of a textile yarn comprising the steps of: - arranging a yarn splicer device (4) having a pair of opposite plates (8,12) which are rotatable with respect to a common drive axis (X-X), - the plates (8,12) being spaced apart from each other, along said drive axis (X-X), so as to identify a passage path (14) of a first yarn (16) ending with a first thread (20) and a second yarn (24) ending with a second thread (28), to be mutually spliced, - arranging tail tearing means (32) comprising a first pair of counter-rotating rotatable cylinders (44) and/or a second pair of counter-rotating rotatable cylinders (48), - grasping and tearing tails (36) of said first and second thread (20,28) by means of said first pair of rotatable cylinders (44) and/or said second pair of rotatable cylinders (48), respectively.
  12. Method according to claim 11, comprising the step of pulling and tearing by modifying the speed and the rotation stroke of said first and second pair of rotatable cylinders (44,48) as a function of the type, material and/or titre of the yarn to be treated.
  13. Method according to claim 11 or 12, comprising the step of tearing the tails (36) of said first and second thread (20,28) according to a radial direction, perpendicular and incident with the drive axis (X-X) of the opposite plates (8,12).
  14. Method according to claim 11, 12 or 13, comprising the step of arranging a yarn splicer device (4) according to any of claims 1 to 10.
  15. Method according to any one of claims 11 to 14, comprising the step of using said first pair of counter-rotating rotatable cylinders (44) and/or said second pair of counter-rotating rotatable cylinders (48) as stretching means of the first yarn (16) and/or of the second yarn (24) in the untwisting step.

Description

FIELD OF APPLICATION The present invention relates to a yarn splicer device with improved tail tearing means and the related operating method. STATE OF THE ART As is known, yarn splicers are devices widely used in the textile sector to restore the continuity of a yarn following a break or a cut when a quality defect of the yarn is detected. Different types exist on the market, which fundamentally differ based on the physical principle which govern the splicing (mechanical, air, etc.), and are chosen according to the specific features of the yarn to be treated. In particular, the use of mechanical splicers is known, such as that illustrated in patent US4637205A (figure 1), which splices two yarn ends, Y1 and Y2, respectively, without knots by means of the splitting and subsequent rearrangement of the twists by means of a pair of counter-rotating, mutually facing friction discs (or plates) aligned along the same rotation axis (Twinsplicer ®). This splicing technology, with respect to the other solutions present on the market, is widely appreciated for the results achievable in terms of quality, strength and stability of the splicing, moreover for a wide range of fibres and titres. Furthermore, the operation occurs according to a purely mechanical principle, with the great advantage that the yarn can be controlled and guided during all the splicing steps. Briefly, the mechanical splicing cycle with discs comprises the following main steps: introducing the two yarns;untwisting and stretching the two yarns;clamping the two yarns in the central area and tearing/removal of the excess tails;tails/yarn coupling;retwisting;opening the discs and extracting the splice. In the sequence of the cycle described above, the removal of the excess tails undoubtedly represents one of the most critical steps to be managed to ensure the good success of the splice in terms of aesthetic appearance and strength. The main reason is primarily due to the fact that the threads to be discarded must be separated by gradual fraying, in order to better prepare them for the subsequent coupling and retwisting step. For this reason, in the devices of the prior art the tearing of the excess tails occurs substantially by traction, by means of a pair of clamps which precisely exploit the absence of twisting (and thus of mechanical strength) of the fibres already parallel within the discs. The characteristic narrow and tapered "foxtail" shape of the splice, which derives precisely from the traction shredding of the fibrils, is by its nature a trait which is difficult for the tearing members to control and manipulate. In particular, there is a residual risk that: the tearing occurs outside the splicing area defined by the two plates, giving rise to macroscopic defects, such as untwisted tails which protrude from the splice;the removed fibrils undesirably adhere to the threads to be preserved, disturbing the correct path of the threads and increasing the risk of frays. To overcome such drawbacks, it is very important that the tails are torn as unidirectionally as possible, in a substantially radial direction with respect to the rotation axis of the mutually facing plates, in order to manipulate the tails with firmness and repeatability. Unfortunately, this demand does not find easy practical response, because it firstly implies the provision by the splicer of a large portion of space, so as to allow the tear levers to move radially without imposing deviations to the tails, to the evident detriment of the compactness of the device. This aspect becomes even more onerous and evident when treating stretch yarns, which, as is known, require greater tear strokes by virtue of their elastic properties. For this reason, in the devices of the prior art the tear stroke is distributed in two directions, first radial and then axial with respect to the plates, thus imposing complicated movements combined with the levers responsible for such a function. Obviously, for the reasons mentioned above this configuration implies a series of drawbacks, firstly the poor ability to control the tails, which typically results in the formation of defects in the splicing area. Patent IT201900021258A1 proposes tail tearing means comprising a pair of clamps rotatable around respective pins to grasp the tails and pull them outside the splicer according to a substantially radial direction with respect to the plates. However, for the above reasons this implies an increase in the overall dimensions of the device in operation and a limitation in the range of workable yarns (especially stretch yarns) for the above reasons. Ultimately, therefore, the solutions of the prior art involve: a temporary increase in the dimensions of the splicer, and therefore of the space which must be reserved for it for the completion of its cycle, to the detriment of compactness;the adoption of complicated movements aimed at limiting the movement of the stretching members, for example by distributing the s