Axially compressible yarn windings waps tube

Abstract: An axially compressible tubular carrier or dye tube for the winding of yarns; the carrier (10) comprises end annular elements (11, 12) and intermediate ring members (13) interconnected each other by flexible connecting elements (17) which define the winding surface (14) for the yarn. The connecting elements (17) comprise rigid projections (18) which are angularly spaced and extend axially from both sides of the intermediate rings (13) and which define groups of projections in which the projections (18) in each group are connected to the projections (18) of a group of projections (18) of an adjacent ring (13) by slanted and elastically flexible linking members (19) whose inclination is reversed when the carrier (10) is axially compressed.

Description: The present invention relates to a tubular carrier or dye tube for the winding up of yarns, and more particularly concerns an axially compressible or collapsible tube which can be used for the winding and dyeing of textile threads and yarns; the axially compressible tube comprises a cylindrical or frustoconical winding surface for winding up yarns, defined by a set of coaxially arranged annular or ring elements which extend parallel to each other and which are connected by flexible linking elements. Axially compressible tubular carriers or tubes for the winding and dyeing of yarns are known for example from US-A- 3,465,984. These carriers are substantially composed of a plurality of parallelly arranged annular or ring elements joined by flexible connecting elements which are suitably shaped so as to facilitate the axial compression of the tube. The yarn winding-up tubes according to US-A- 3,465,984 have considerable applicational limitations and drawbacks because they do not ensure a sufficient degree of the dimensional stability of the tube, both in the extended condition and in the compressd condition, on account of the elastic behaviour of the transverse elements, connecting the rings. Moreover, the axial compressibility of the tube cannot be correctly controlled in any way as would be otherwise be desirable in order to ensure uniform and homogeneous compression and dyeing of the winded yarn. Furthermore, uniform axial unwinding of the yarn, after compression, may be partially prevented or compromised as a result of pinching of the yarn by projecting portions of said flexible connecting elements. In EP-A- 0 348 721 is disclosed a carrier for winding yarn in the form of an axially compressible tubular body comprising end ring elements and intermediate ring elements axially aligned and parallelly arranged to each other, said ring elements are interconnected by elastically flexible connecting elements and a plurality of axially projecting bar members uniformly spaced apart on both side and over the entire periphery of each ring element to limit the axial compression of the tubolar body, said connecting elements comprising elastically flexible linking members arranged at an angle with respect to the axial direction of the the carrier. In EP-A- 348721, but also in US-A- 4,181,274 and US-A- 4,379,529, tubes are disclosed which are axially compressible in a controlled manner, there being provided axially protruding elements between adjacent rings which, prevent the ring members of the tube to move closer beyond a predetrmined point. Although these documents suggest the use of rigid tube structures which are able to maintain a stable shape during winding of the yarn and which then yield axially during compression, they nevertheless do not solve completely and satisfactorily the problem of providing a tube having a stable structure both in the completely extended condition and in the compressed condition of the tube while, maintaining it free from deformations or projecting parts so as to preventing the pinching and to allow correct unwinding of the yarn after the dyeing process. In particular, due to recovery or the spring bach movement of the plastic material from which they are moulded, said tubes do not allow a structurally stable condition to be maintained upon removal of the compressive forces; furthermore, the shape and arrangement of the flexible elements connectint the rings which make up the tube may cause deformation or rotation of the rings themselves, negatively effecting both the dyeing operation and the unwinding of the yarn from the tube in the compressed condition. US-A- 4,560,116 also discloses a carrier for yarns in the form of an axially compressible tube consisting of a plurality of annular elements provided with V-shaped portions axially aligned in parallel rows and peripherally arranged in relation to the tube; the V-shaped projections of a ring are connected to corresponding V-shaped projections of adjacent rings by flexible transverse connecting elements which are inclined relative to the longitudinal axis of the tube and whose angle of inclination is reversed when the tube is in the compressed condition. Although such a tube structure ensures a certain degree of dimensional stability in the completely extended condition, so as to withstand the radial compressive forces exerted by the yarn during winding, it does not allow any control of axial compression degree and does not ensure any dimensional stability of the tube after compression; in fact, the V-shaped configuration of the projecting parts of the rings and their axially aligned arrangement do not prevent the individual rings of the tube from deforming radially and do not allow the tube to remain in a stable compressed condition which ensures easy axial unthreading of the yarn. Moreover, owing to the absence of stop elements between the ring members, during compression of the tube the V-shaped projections could cause the pinching and breakage of the yarn and the breakage of the transverse connecting elements thus preventing uniform unwinding of the yarn. The object of the present invention is to provide a tubular carrier or tube for receiving textile threads and yarns, in particular for dyeing operations, which is both axially compressible and which satisfies the following requirements: a) it must have a degree of axial compression controlled by stop elements which limit the compression of the tube to a predetermined length b) it must not cause twisting and deformation in respect of the diameter of the tube during compression, and avoid pinching or breakage of the first turns of yarn directly wound onto the tube; c) when the yarn is to be used, after dyeing, it must allow moreover uniform unwinding and a complete unthreading of the yarn in the axial direction, so that all of the actual yarn can be used; d) it must provide a tube structure such as to ensure dimensional stability both in the extended and in the compressed condition of the tube, avoiding in this latter case any spring back movement and breakage of parts of the same tube. A further object of the invention is to provide a tubular carrier for yarns which, in addition to ensuring the advantages referred to above, has an extremely simplified design, such that it can be manufactured by moulding from plastic materiales, resulting in a tube structure which is integral and free of defects or of incorrectly formed and incomplete parts. All of the above can be achieved by means of a yarn carrier in the form of an axially compressible tubular element comprising the characteristic features of the main claim. A preferential embodiment of a tube for winding up yarns according to the invention will be illustrated in detail hereinbelow with reference to the accompanying drawings, in which: Fig. 1 is a view of the tube in the extended condition; Fig. 2 is a view of the same tube in the axially compressed condition; Fig. 3 is a cross-sectional view along the line 3-3 of Fig. 1; Fig. 4 is an enlarged and developed plan view of a portion of the tube of Fig. 1; Fig. 5 is an enlarged sectional view along the line 5-5 of Fig. 4; Figs.6, 7 and 8 show enlarged details of the tube of Fig. 1, illustrating the three most important moments during axial compression of the tube, from the condition in Fig. 1 to the condition in Fig. 2. As shown in the extended condition of figure 1, the tube 10 comprises at both ends main annular elements 11 and 12 suitably shaped so as to allow stacking of the tubes themselves; the tube body also comprises a plurality of intermediate ring elements 13 axially aligned with respect to each other and parallely arranged so as to define a winding surface 14 for winding-up yarn, said winding surface 14 having a cylindrical or conical shape depending on the required configuration of the tube. The tube 10 at its two ends may have a first non-compressible section 15 comprising a plurality of rigid connecting elements 16, uniformly spaced out in the circumferential direction, which extend axially from each annular end element 11 and 12 towards a first intermediate ring 13. As shown in the same Figure and in the enlarged detail of Fig. 4, the intermediate rings 13 are joined together by connecting elements having an intermediate portion which is elastically flexible, i.e. is able to allow a controlled axial compression of the tube 10 maintaining its dimensional stability both in the extended condition of the tube (Fig. 1) and in the compressed condition shown in Fig. 2. These flexible connecting means 17 for the rings 13 comprise a plurality of rigid projections or bar members 18 which extend longitudinally on each side of the rings 13, with the exception of the end ones; the bar members 18 have a predetermined length less than the distance initially existing between adjacent rings 13 in the extended and uncompressed condition of the tube shown in Fig. 1. The bars 18 of each ring 13 are uniformly spaced around with respect to each other and are located in intermediate positions with respect to the bars 18 of the adjacent rings so as to form alternate comb-like arrangements where each of the bars of one ring is disposed between bars of an adjacent ring. The bars 18 of the rings 13 therefore have a calculated length such as to permit the desired degree of axial compression of the tube 10; moreover, the bars on one side of a ring extend axially beyond the ends of the bars on the opposite side of an adjacent ring so as to define, with the rings 13, the winding surface 14 for winding up an yarn. According to the present invention, as shown in detail in Fig. 4, the bars 18 between two adjacent rings 13 are subdivided into groups of bars denoted by 17a and 17b in Fig. 4, the bars 18 of each group being interconnected by means of bridge connecting elements or elastically flexible linking members 19 which are alternately slanted in different or opposite directions with respect to the axial direction of the tube; the linking members 19 preferarbly form an angle of between 15° and 22° and in general their inclination must be such as to allow a controlled axial compression of the tube and reversal of the inclination itself in the compressed condition of the tube, as will be explained below, so that the tube shape behaves stably both in the extended condition shown in Fig. 1 and in the compressed condition shown in Fig. 2. Overall, therefore, the tube 10 assumes a tubular shape with a mesh-like structure so as to allow winding-up of the yarn and passage of the dye bath in a uniform and homogeneous manner. The configuration of the rings 13, the bars 18 and the linking members as well as their arrangement must be such as to prevent distortion of the tube and the formation of projecting parts with respect to the yarn winding surface 14, which could damage or at any rate cause pinching of the yarn itself during compression of the tube. For this purpose, as shown in the section in Fig. 5, the fore or external surface of each bar 18 is flat shaped and is arranged slightly set back with respect to the external peripheral surface of the rings 13; the end of the same bar has a rounded external edge so as to prevent the bar interfering with the turns of wounding yarn when the tube is compressed or collapsed. Similarly, the flexible linking members 19 are slightly set back with respect to the yarn winding surface 14 defined by the external edge of the bars 18 and rings 13 of the tube. With reference now to Figures 6, 7 and 8, we shall describe the mode of operation of the tube 10 during the transition from the extended condition of Fig. 1 to the compressed condition of Fig. 2. As previously mentioned, the bars 18 of the rings 13 are subdivided into groups, with the bars of each group being interconnected by flexible linking members 19; as shown in Fig. 4, each group of bars is separate and distinct from the adjacent groups 17, that is to say the bars 18 at the ends of two adjacent groups 17 are not connected by linking members 19. Therefore, each group of bars is able to undergo stresses and slight flexures in the circumferential direction completely independently of the adjacent groups of bars, thereby ensuring a stable axial compression of the tube without dangerous deformations and always keeping the annular elements 13 axially aligned relative to each other and free from distorsions. In particular, the points where the linking members 19 join the two adjacent bars 18 are sat back slightly with respect to the ends of the bars themselves. If we examine, therefore, Figures 6, 7 and 8 of the drawings, Fig. 6 shows the arrangement of two annular elements o ring 13 and of three adjacent bars 18, i.e. one bar of the upper ring and two bars of the lower ring which bars are joined by the linking members 19, in the condition which these parts assume when the tube is completely extended or not compressed, as shown in Fig. 1. In this condition, the rings 13 are unable to move away from each other, or to move towards each other or to rotate, this being prevented by the linking members 19 connecting the bars 18 and by the slanted arrangement of the linking members themselves. In this condition, the bars 18 of one ring are spaced apart from the other ring, extending a certain amount beyond the ends of the bars of the latter. The tuba 10 in the extended condition therefore has a structure which is highly stable with respect to the radial compressive stresses caused by winding-up of the yarn. When the tube 10 rust be compressed inside a dyeing autoclave, the tube is made to collapse, thus causing the rings 13 to move towards each other without undergoing rotations or distortions remaining centred, until the bars 18 of each ring stop against the opposite surface of next ring, Fig. 8, thus acting as stop elements for stopping the rings 13 and controlling the degree of axial compressibility of the tube 10. As can be seen in Fig. 8, after compression, the linking members 19 have an inclination which is reversed compared to that of Fig. 6; in order to reach this condition they have to pass through the intermediate condition of Fig. 7 in which the linking members 19 are elastically compressed; therefore, during the transition from the condition of Fig. 7 to that of Fig. 8 they behave like an elastically loaded spring, suddenly reversing their inclination after completely discharging the elastic compression previously stored. Therefore, the tube 10 will be stably self-held in its new compressed configuration shown in Fig. 2, in which the bars 18 are all in contact with opposite rings 13 so as to offer a practically continuous surface for supporting the yarn. Therefore, the yarn can be axially wound in a uniform and continuous manner, without being pinched or retained by the tube or encountering projecting parts which could prevent unthreading. From the explanations and illustrations it is therefore obvious that an axially compressible tubular carrier for textile threads and yarns has been provided, comprising annular elements which are parallelly and coaxially arranged relative to each other and are provided with axially projecting bars or rigid elements for stopping the rings said bars and the ring members, defining the yarn winding surface; groups of bars between adjacent rings are connected by elastically flexible connecting elements arranged at an angle with respect to the axial direction of the carrier and the annular or ring elements of the yarn carrier are provided with axially oriented stop means which allow the maximum compression of the tube to be controlled, causing reversal of the angles of orientation of the flexible elements connecting the bar. In this way, a carrier for yarns is achieved in the form of a tubular element with a meshwork structure, designed to allow the passage of fluids for the treatment of yarns, said car having a hihgy stable shape which is not subject to deformations of the yarn winding surface both in the extended and in the compressed condition of the carrier. Therefore, it will be understood that the explanations and illustrations with reference to the accompanying drawings have been provided solely by way of example of the innovative principles of the claimed invention.

Claims: A carrier for winding-up yarns, said carrier being in the form of an axially compressible tubular body (10) comprising end ring elements (11, 12) and intermediate ring elements (13) axially aligned and parallely arranged to each other, said ring elements (13) being interconnected by elastically flexible connecting elements (17) and a plurality of axially projecting bar members (18) uniformly spaced apart on both sides and over the entire periphery of each ring element (13) to limit the axial compression of the tubular body (10), said connecting elements (17) comprising elastically flexible linking members (19) arranged at an angle with respect to the axial direction of the carrier, characterized in that said bar members (18) of one ring elements (13) being arranged in intermediate positions and extending beyond the ends of the facing bar members (18) of an adjacent ring element (13), and in that the facing bars members (18) of adjacent ring elements (13) are provided in independent groups in which the ends of said bar members (18) on the one ring element (13) are connected by said flexible linking member (19) to the ends of said bar members (18) on the adjacent ring element (13) by said linking members (19), which are arranged alternately slanted in opposite directions. A carrier according to Claim 1, characterized in that the said stop means comprise said axially protruding bars (18). A carrier according to Claims 1 or 2, characterized in that said bar members (18) have an external yarn-winding surface which is set-in slightly with respect to the external surface of said ring elements (13). A carrier according to Claims 1 or 2, characterized in that the external edge at the end of each of said bar members (18) has an inwarly curvet profile. A carrier according to Claim 1, characterized in that said flexible linking members (19) form an angle of between 15° and 22° with respect to the axial direction of the carrier. A carrier according to Claim 3, characterized in that the said bar members (18) have a flat external surface. A carrier according to Claim 1, characterized the points where the flexible linking members (19) join the bar members (18) are set back with respect to the ends of the same bar members (18). A carrier according to Claim 1, characterized in that a non-compressible rigid section (15, 16) is provided between the end ring elements (11, 12) and an intermediate ring element (13). A carrier according to Claim 1, characterized in that the length of the bar members (18), the length of the flexible linking members (19) and the angle formed by the latter with the axial direction of the carrier are such as to maintain said flexible linking members (19) in an unstressed and stable condition both in the extended and in the axially compressed conditions of the carrier.

Inventors: ROBERTI PASINI, ROBERTI, PASINI
Applicants: TUBETTIFICIO EUROPA SPA, TUBETTIFICIO EUROPA S.P.A.
Application year: 1991
Main classification: D06B23
IPC codes: D06B23