DEVICE FOR FORMING WINDINGS OF YARN AND RELATED APPARATUS FOR THE STEAMING OF YARNS

Abstract: The yarn (F) is wound in coils onto a winding core (27) with at least a portion of the coils not being engaged with the winding core. Screw entrainment means (19) are provided in correspondence with this portion and act on the coils of yarn, causing them to advance in the direction of winding. The apparatus (1) comprises a steaming chamber (2) with steam heating means (10) which act on the upper wall of the chamber. The arrangement avoids condensation of the steam on the upper wall of the steaming chamber (2) and consequent dripping of the condensate onto the yarn which is being treated. Preferably, the winding is formed within the steaming chamber (2) to avoid the yarn tending to curl and form knots.

Description: The present invention relates in general to the treatment of yarn and is particularly concerned with the formation of windings of yarn intended to be subjected to a treatment such as steaming. For this purpose, starting with the yarn wound tightly onto a reel or bobbin in a condition in which it cannot be treated, a generally looser winding is formed. The latter is deposited on a transporter, such as a conveyor belt, which carries it into the treatment chamber. The winding of yarn is prepared by winding the yarn to be treated onto a winding core extending in a fixed direction of winding. Devices are known in the art for forming windings of yarn, which include a winding core with an input end and an output end and with a rotary head for supplying the yarn which is able to wind the yarn into coils around the input end of the winding core. The winding advances on the core towards its output end due to entrainment by the transporter. The main object of the present invention is to provide a method and a device which ensure, in all operating conditions, the regularity of the winding of the yarn onto the core and its gradual advancement towards the output end of the core itself. According to a first aspect of the present invention, this object is achieved by virtue of a method for forming windings of yarn, according to Claim 1 below, and a device designed to carry out this method, according to Claim 5. In another of its aspects, covered by Claim 11 and the following Claims, the invention also relates to apparatus for incorporating a winding device of the type specified above. The invention will now be described, purely by way of non-limiting example, with reference to the appended drawings, in which: Figure 1 shows schematically in longitudinal vertical section the structure of apparatus for the steaming of yarns, produced according to the invention, Figure 2 is a section taken on the line II-II of Figure 1, Figure 3 is a section taken on the line III-III of Figure 2, on an enlarged scale, Figure 4 is a view taken on the arrow IV of Figure 3, and Figure 5 is a longitudinal vertical section substantially similar to Figure 1, which illustrates a possible variant of the apparatus according to the invention. In Figures 1 and 2, apparatus usable for subjecting a yarn F to steaming is generally indicated 1. The yarn F is unwound from a supply reel or bobbin B₁ to be rewound onto a collecting reel or bobbin B₂ after treatment. The steaming is carried out by exposing the yarn to the action of the steam which collects in the treatment chamber 2 of the apparatus. For this purpose, an elongate winding of generally loose coils of yarn is formed from the yarn F supplied from the bobbin B₁, by means of a device 3 whose structure will be better explained below with reference to Figures 3 and 4, so as to enable good penetration of the steam into the yarn. According to a widely known solution, the winding of yarn formed by the device 3 is placed on a transporter device, for example a conveyor belt 4, which advances the winding from an inlet opening 5 to an outlet opening 6 provided in the walls of the chamber 2. The upper pass of the conveyor 4 which receives the yarn is supported by rollers or pulleys arranged in such a way as to give the pass a profile in which an initial ascending section (in the direction of advance of the yarn), a central approximately horizontal section, and a final descending section can be distinguished. At the outlet from the treatment chamber 2, which is generally prismatic in shape, the winding of yarn is passed over a ve ntilator device 7 operated by a suction element 8, in order to cool the yarn before it is rewound onto the collecting reel or bobbin B₂. As better seen in the section of Figure 2, the apparatus 1 may in fact include one or more transporter devices 4 (in the example illustrated, ten) each of which advances a winding of yarn formed by a device of the type indicated 3 in Figures 3 and 4 into the chamber 2. The heating in the chamber 2 and the diffusion of the steam within the chamber is effected through a steam distribution duct 9 (connected to a source of steam, not illustrated in the drawings) including a main branch 10 and a secondary branch 12. The main branch 10 extends near (and preferably over) the upper wall or head 11 of the chamber 2, while the secondary duct 12 conveys the steam towards a grid or coil 13 which extends within the chamber 2 in its base region, which is completely open or at any rate provided with apertures, in a position below the transporters 4. The steaming chamber 2 is surrounded by an outer casing 14 of thermally insulating material. The steam supplied by the main duct 10 emerges through holes 15 provided in the duct and diffuses into the space between the upper wall 11 of the chamber 2 and the casing 14 of insulating material, heating the chamber 2 from its upper wall 11. Subsequently, the steam issuing from the main duct 10 is propagated downwardly inside the casing 14 and enters the steaming chamber 2 from the bottom. The vapour from the duct 10 thus penetrates the chamber 2 from its (open or at any rate apertured) base region where the coil 13 is situated so as to be able to give up heat to the steam supplied to the chamber 2, to prevent the temperature of this steam falling below predetermined values. Since the chamber 2 is heated from its top wall 11, using steam which is only subsequently introduced into the chamber 2 itself, the upper wall 11 is certain to remain at a temperature which is even a little higher than the temperature in the chamber 2. In this way, condensation of the steam on the wall 11 and consequent dripping of any condensate formed onto the yarn F which is being treated is completely avoided. In Figure 3, a motor, for example an electric motor, is indicated 16 and is provided with a shaft 17 which is traversed by a longitudinal cavity 18 at least in its portion extending within the motor 16 itself. A screw 19 including a core 20 and at least one thread 21 is mounted on the free end of the shaft 17, that is, the end opposite the body of the motor 16. A rotary head, indicated 22, has a generally bell-shaped configuration with an apex part rigidly keyed to the shaft 17 and a circular end edge 22a extending in a plane perpendicular to the axis of the shaft 17, in substantial alignment with the free end of the shaft 17. The bell 22 is traversed by a cavity 23 which extends along one of the "generatrices" of the bell and is connected in the region of the angle 24 with the cavity 18 of the shaft 17. At the opposite end, that is, at the free end of the head 22, the cavity 23 has an opening 25 facing the screw 19. The cavity 18 and the cavity 23 together define a duct for feeding a yarn F towards the opening 25. The yarn F is introduced, usually by pneumatic means, into the cavity 18 from the rear of the motor 16, that is, the end opposite the bell 22. The yarn passes into the cavity 23 and from the latter towards the opening 25, advancing continuously through the cavities 18 and 23 due to the rotation of the bell 22 caused by the operation of the motor 16. Two lining sleeves of ceramic material are indicated 26 and have the function of preventing the yarn from wearing grooves in the material (usually metal) of the shaft 17 and the bell 22, in the regions of the angle 24 and the opening 25, as it advances rapidly (600-1000 m/min) within the cavities 18 and 23. Since the head 22 must be rotated at high speed in order to ensure the speed of advance indicated, a further cavity 23a which is completely identical to and symmetrical with the cavity 23 (baricentrically symmetrical) is provided in the head 22. Thus, the head 22 is prevented from becoming unbalanced and oscillating or vibrating during rotation. A fork element is generally indicated 27 and is arranged to act as a core for the winding of the yarn F. The fork element 27 is constituted by a base part 28 which is generally sleeve-shaped, and two arms or prongs 29 which extend from the sleeve 28. The sleeve 28 is fitted onto the shaft 17 in an intermediate position between the base part of the bell head 22 and the end on which the screw 19 is mounted, with the interposition of bearings 28a which allow the sleeve 28 and the fork 27 to rotate freely together relative to the shaft 17, that is, not to be forced to rotate when the shaft 17 rotates due to the operation of the motor 16. As can be seen in Figure 3, in the final assembled arrangement, the two arms or prongs 29 of the fork 27 extend from the sleeve 28 away from the bell head 22. Each arm 29 has an upstream or input end 30a situated in correspondence with the free end of the bell 22a and the screw 19, and a respective free or output end 30b. In general, the two arms 29 are located in symmetrical positions relative to the axis of the shaft 17, which coincides with the axis of symmetry and rotation of the screw 19. The yarn which emerges from the aperture 21 is wound onto the two arms 29 of the core 27, as better illustrated in the sectional view of Figure 4. The bell head 22 is in fact rotated by the shaft 17 of the motor, while the winding core 27 is kept in a fixed position (by means which will be better explained below). Consequently, the yarn is wound onto the core 27 to form coils of which two opposite portions S₁, S₂ are discernible and which extend freely between the two arms 29. The free portions of each coil S₁, S₂ also rest on the core 20 of the screw 19 and are thus exposed to the entrainment action exerted by the thread 21, the sense of which is selected so as to cause the forced advance of the coils which are gradually formed on the core 27 from the input end 30a towards the free or output end 30b of the arms. In this way, a winding of yarn F is formed which may be deposited on the upper pass of the conveyor 4 to be advanced subsequently into the steaming chamber 2. The input end of the conveyor 4, constituted by a roller or pulley 31 for driving the conveyor belt, is brought into contact with the winding core 27 immediately downstream of the region in which the screw 19 acts as a positive driving element. The wheel or pulley 31 is preferably mounted on a support apparatus 32 (Figure 1) which is kept resiliently (or at any rate so that its position can be varied) in contact with the lower face of the winding core 27. The fact that the core 27 is, so to speak, resting on the wheel or roller 31 ensures that the core remains securely in a fixed position and is not thus rotated by the shaft 17 due to friction. At the same time, the fact that the position of the wheel or roller 31 is adjustable (for example, with a resilient mounting schematically illustrated here by a spring 33) enables this position to be adapted precisely to the variations in diameter (count) of the yarn which is being wound. In the embodiment illustrated in the drawings, the arms 29 of the winding core 7 converge slightly. In this way, it is possible to allow for any shrinkage of the yarn which may occur immediately after the winding has been formed. In this connection, a solution can also be envisaged in which the conveyor belt 4 is eliminated, while the arms 29 of the core 27 and the screw 19 are lengthened so as to act as elements for guiding and transporting the win ding of yarn which advances into a chamber for steaming or treatment generally. In this case, the diametral dimensions and the relative positions (convergence) of the arms 29 of the winding core 27 could be selected so as to allow exactly for the shrinkage of the yarn due to the treatment. For the purpose of this possible configuration of use, the use is envisaged (and therefore fully encompassed by the scope of the present invention) of winding cores 27 in which the positions and/or the inclinations of the arms 29 relative to the sleeve 28 are selectively variable and adjustable (by means of screws). The use may also be envisaged of a screw 19 having a core 20 and/or threading 21 generally tapered away from the input end 30 of the winding core 27. Moreover, as regards the general configuration of this core, solutions may be used which are of different types from those illustrated in the drawings but which still provide for at least one free portion of the coils of yarn to be subjected to the driving action of the screw 19. As far as the general configuration of the apparatus 1 is concerned, the Applicant has been able to observe that with some types of yarn, such as so-called "single filament", that is non-multiple, yarns, the solution illustrated in Figure 1 may sometimes give rise to phenomena of curling and knot formation. These phenomena inhibit the subsequent operation of rewinding the steamed yarn onto the collecting bobbin. These problems are, however, completely eliminated if, according to the solution illustrated in Figure 5, the winding of yarn to be steamed is formed inside the steaming chamber. This may be achieved by inserting the device or winding head 3 within the inlet opening 5 of the steaming chamber 2, so that the winding of yarn F to be steamed is formed inside the chamber 2, not outside as in the solutions according to Figure 1. At the outlet of the chamber 2, the winding of yarn is passed over the ventilation device 7 operated by the suction element 8, in order to cool the yarn before it is rewound onto the collection reel or bobbin B₂. According to the solution already described in detail with reference to Figure 1, the heating of the chamber 2 and the diffusion of the steam within the chamber is effected through the steam distribution duct 9 with its main branch 10 which extends near the upper wall or head of the chamber 2, and its secondary duct 12 which conveys the steam towards the grating or coil 13 extending in the bottom of the steaming chamber. According to an advantageous improvement, a shaped cover 60 is associated with the outlet opening 6 of the chamber 2 and extends like a roof above the outlet opening 6 towards the outside of the steaming chamber 2. The function of the cover 60 is to protect against the escape of steam from the steaming chamber. The return pass of the conveyor belt 4 extends beneath the steaming chamber 2 and re-enters the steaming chamber 2 through an opening 50 provided in the base wall of the chamber in the region immediately below the inlet opening 5 in which the winding device 3 is inserted. As in the case of Figure 1, the device 3 is substantially constituted by a winding core 27 including two converging arms on which the yarn F is wound in coils due to the rotation of the head 22 driven by the hollow shaft 17 through which the yarn F, unwound from the reel or bobbin B₁, enters the device 3. The winding of yarn formed by the rotation of the head 22 is advanced along the arms of the winding core 27 by the screw 19 which is also driven by the shaft 17. In the solution illustrated in Figure 5, the shaft 17 is driven by a motor 16 through a belt or chain transmission 16a. The motor 16 may thus be located in a position out of alignment with the shaft 17, so as to permit the free passage of the yarn towards the winding device. A further motor (geared motor) 40 arranged below the de vice 1 drives the conveyor 4 through a driving pulley 41.

Claims: 1. A method for forming windings of yarn (F), in which the yarn is wound on a winding core (27) extending in a fixed direction of winding, characterised in that: - the yarn is wound in coils on the core (27), the yarn (F) being kept disengaged from the core (27) in at least one portion (S₁, S₂) of the coils, and - screw entrainment means (19) are made to act in the fixed direction of winding on the at least one portion (S₁, S₂) of the coils of yarn (F) wound on the core (27). 2. A method according to Claim 1, characterised in that the screw entrainment means (19) are made to act on the inside of the coils of yarn (F). 3. A method according to Claim 2, characterised in that the coils are wound along a closed winding path (S₁, S₂), and in that the screw means (19) used include screw thread elements (21) with a circular development for cooperating with the coils in at least two portions (S₁, S₂) of the coils. 4. A method according to any one of Claims 1 to 3, characterised in that the yarn wound on the core (27) is deposited on a transporter device (4), and in that the screw entrainment means (19) finally disengage from the coils of yarn immediately before the yarn is deposited on the transporter device (4). 5. A winding device for forming windings of yarn, comprising a winding core (27) having an input end (30a) and an output end (30b), and a rotary head (22) for supplying the yarn (F) and for winding the yarn (F) in coils around the input end (30a) of the winding core (27), characterised in that: - the winding core (27) includes at least two arms (29), between which at least one free portion (S₁, S₂) of each coil of yarn (F) can extend, and - screw entrainment means are provided which extend between the at least two arms (29) of the winding core (27) from the input end (30a) and are able to cooperate with at least one free portion (S₁, S₂) of the coils of yarn, for entrainment thereof, to cause the advance of the yarn (F) wound on the core (27) towards the output end (30b). 6. A device according to Claim 5, characterised in that the winding core (27) includes two arms (29) which are side by side so that each coil of yarn (F) includes two opposite free portions (S₁, S₂), and in that at least one motorised entrainment screw (19, 16) is provided which is interposed between the adjacent arms (29) and is coextensive therewith, the screw (19) being provided with an external thread (21) for cooperating with both the two opposite free portions (S₁, S₂) of the coils of yarn (F). 7. A device according to Claim 5 or Claim 6, characterised in that it includes a motor (16) with a common shaft (17) for driving the rotary head (22) and the screw means (19), in that the screw means (19) are arranged at one end of the shaft (17), while the rotary head (22) is keyed to the shaft (17) and has a general bell shape which diverges towards the end of the shaft (17), and in that the shaft (17) is at least partially traversed by a longitudinal cavity (18) for supplying the yarn (F) towards the rotary head (22). 8. A device according to Claim 7, characterised in that the rotary head (22) has a peripheral opening (25) for supplying the yarn (F) towards the winding core (27), a first respective cavity (23) for the passage of the yarn (F) from the longitudinal cavity (18) of the shaft towards the peripheral opening (25), and a second respective cavity (23a) baricentrically symmetrical with the first cavity (23). 9. A device according to Claim 7 or Claim 8, characterised in that: - the winding core (27) is generally fork-shaped with a base part (28) which is freely rotatable (28a) on the common drive shaft (17) in an intermediate position between the rotary head (22) and the s crew means (19), and - a device (4) is provided for transporting the yarn (F) wound on the core (27), which is able to cooperate with the core (27) in a relationship of relative support so as to prevent the core (27) from being rotated by the shaft (17). 10. A device according to Claim 9, characterised in that the transporter device (4) carries associated adjustment elements (31, 32, 33) for selectively varying the relationship of relative support between the transporter device (4) and the winding core (27). 11. Apparatus for steaming and winding of yarn (F), comprising a winding device (3) for forming coils of yarn, a steaming chamber (2) with an upper wall (11), an inlet opening (5) and an outlet opening (6) for the yarn (F), and transporter means (4) for transferring the yarn from the inlet opening (5) to the outlet opening (6) through the steaming chamber (2), characterised in that it includes: - main steam heating means (10) acting on the upper wall (11), and - steam conveying means (14) for transferring the steam from the main heating means (10) into the steaming chamber (2). 12. Apparatus for steaming a winding of yarn, comprising: - a winding device (3) which is able to form a generally loose winding of yarn to be steamed and, - a steaming chamber (2) with an inlet opening (5) and an outlet opening (6) for the yarn, characterised in that the winding device (3) is inserted in the inlet opening (5) so that the winding of yarn is formed inside the steaming chamber (2). 13. Apparatus according to Claim 11 or Claim 12, characterised in that a shaped cover (60) is associated with the outlet opening (6) and extends outwardly of the steaming chamber (2) to act as protection against the escape of steam from the chamber (2). 14. Apparatus according to any one of Claims 11 to 13, characterised in that a closed loop conveyor belt (4) is provided for transporting the yarn (F) from the inlet opening (5) to the outlet opening (6), and in that a further opening (50) is provided for the belt (4) to enter the steaming chamber (2), situated in a generally lower position than the winding device (3). 15. Apparatus according to any one of Claims 11 to 14, characterised in that the winding device (3) includes a winding core (27), a rotary head (22) for supplying the yarn (F), which is able to wind the yarn (F) in coils around the winding core (27), and screw entrainment means for advancing the coils of yarn on the winding core (27). 16. A device according to Claim 15, characterised in that it includes a common driving shaft (17) for the rotary head (22) and the screw means (19), and a motor (16) for driving the common shaft (17) arranged in a position generally out of alignment with the common shaft (17).

Inventors: LANARO, WALTER
Applicants: LAWER S.R.L.
Application year: 1987
Main classification: B65H54
IPC codes: D06B17, B65H54