AU746733B2 - Reducible-diameter center made of injection-molded plastic for the formation of spools of yarn for dyeing and other treatments - Google Patents

Description

"REDUCIBLE-DIAMETER CENTER MADE OF INJECTION-MOLDED PLASTIC FOR THE FORMATION OF SPOOLS OF YARN FOR DYEING AND OTHER TREATMENTS"

DESCRIPTION

In an earlier intellectual property document belonging to the present proprietor (Utility Model Application FI/92/U/102 of 28.08.92 European Patent No.

93830308.8 Publication No. 0 587 538 of 20.07.93 and U.S. Patent No. 5 435 497 of 23.08.93 granted on 25.07.95) a description is given of a center made of *o injection-moulded plastic for forming a spool of yarn wound about it in turns for processing, especially in 15 dyeing, and for the subsequent unwinding of the yarn.

eo On the cylindrical wall of this center are rows of 0000 elongate slots, the slots of any one row being staggered relative to those of the adjacent rows so that the longitudinal edges of each slot can approach 20 each other in the middle; in this way the center can undergo virtually uniform reduction of its transverse section if centripetal pressure is applied to the cylindrical wall of the center by the turns of the wound yarn, when the yarn shrinks as a result of the 25 treatments applied to the yarn spool. The rows of the S. 05 S" slots may be longitudinal or slightly helical.

The following explanation will be understood more clearly if reference is also made to the drawing, which illustrates the prior art and a non-limiting embodiment of the invention.

In the drawing: Figs. 1 and 2 show a partial view of a prior art center before and after the treatment (dyeing or other) of the spool of yarn; Figs. 3, 4 and 5 show a portion of a center according to the invention in an external view and in sections on IV-IV and V-V as marked in Fig. 3; Figs. 6 and 7 show for comparison and in partial section the conditions of the deformed center of the prior art and of the deformed center when made in accordance with the invention, respectively; Fig. 8 shows the portion of the deformed center of Fig. 7, without the spool of yarn; and Figs. 9 and 10 show a center according to the invention, in an external view and partial section, in the intact condition and in the condition following deformation by contraction.

Shown in Figs. i, 2 and 6 is a portion of the prior art center 101, in the region which includes a step 103 where the opposite end of an identical center o" is positioned so as to sit axially on top of the center 101; the letters BB indicate the spool of yarn gathered on the center 101. When the center 101 with its spool 15 BB of yarn undergoes the requisite treatments (dyeing

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Sand/or other treatments with heat and moisture), the e yarn of the spool BB tends to contract and exerts on the cylindrical wall 105 which contains the rows of slots 107 centripetal pressures which can be very 20 high, while at the same time the strength of the thermoplastic material of the center 101 is weakened by the high temperature to which the whole is subjected.

Under these conditions the center deforms as seen in Figs. 2 and 6, with a reduction in the diameter of the 25 wall 105, while the region of the step 103 remains unchanged; between the deformed wall 105 and the region of the step 103 there develops a tapering intermediate region 109, roughly frustoconical, which is relatively very extensive in the axial direction. It follows from this that within the spool BB, the extreme portion BIB1 (Figs. 2 and 6) contains turns of yarn whose conditions differ from those of the other portions of the spool, since in said portion BIB1 the yarn has been unable to benefit from the shrinkage of the wall 105 and of the reduction of the diameter of said wall and therefore within said portion B1B1 the turns of yarn are under much greater tension and are much tighter than the turns of yarn of the rest of the spool, in the condition of Figs. 2 and 6. The yarn in said portion 3 B1B1 is therefore subject, by comparison with the yarn of the rest of the spool, to alterations of physical characteristics due to the different tensions to which it is subject, and exhibits chromatic differences caused by the lower penetration of the dye due to the greater tightness of the turns and consequent greater compactness of the turns in said portion BIB1.

When the yarn is used in textile manufacture, these chromatic differences and differences of physical characteristics create intolerable irregularities in the fabric in the form of transverse bands where the ""color differs to a greater or lesser extent from that 0@ of the rest of the fabric and/or in the form of *'".transverse bands where the morphology differs to a 15 greater or lesser extent, such as puckering or wrinkling.

The invention provides a center of the abovementioned sort, but it avoids the disadvantages discussed above and achieves other objects and 20 advantages, which will be obvious from the following 00 0 text.

In accordance with the invention, at either or both ends of the perforated cylindrical wall an annular depression is formed, comprising indentations and ribs, 25 in such a way as to bring about the uniform reduction of the transverse section of the perforated cylindrical wall and of the thickness of the center including said annular depression, where the extreme turns of the spool lie.

In practice, adjacent to the stepped profile present at one end of the center, and adjacent to the profile on which the "reserve" of yarn is accumulated, is an annular depression of reduced thickness comprising a first series of ribs and indentations between the profile and said annular depression; another series of indentations is provided between the slotted cylindrical wall and said depression; together, these features serve to produce the reduction in the transverse section of the cylindrical wall of the 0 0 00 0 0 0000 00 00 0

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0 0 4 center even in the vicinity of the abovementioned profiles (the stepped profile and that for the accumulation of the reserve), thereby preventing differences of conditions between the turns of yarn of the spool wound on the center, when the transverse section of the center is reduced as the yarn undergoes its treatment.

The indentations of the first series may be aligned with the indentations of the second series.

Furthermore the indentations of both series may be aligned with the slots and with the gaps between said slots present in the cylindrical wall, so that the pitch between the indentations is one half of the pitch between the rows of slots.

15 The opposite end of the center from that forming the stepped profile is of a similar shape to that defined above and may also be shaped in such a way as to grip the end of the "reserve" yarn, having a thin flat region which is torn by the yarn to be anchored, 20 as disclosed in an earlier intellectual property document (Italian appn. No. FI/95/A/110 of 19.05.95; European Patent Application No. 96830237.2 of 29.04.96 and others) As illustrated in Figs. 3 to 5 and 7 to 10, the 25 center comprises a generally cylindrical wall 51 of relatively great thickness containing slots 53 (equivalent to the slots 107 or similar) arranged in longitudinal alignments, the slots of one row being staggered with respect to those of the adjacent rows; the arrangement could also be modified in that the rows of slots may run in helical lines with a very coarse pitch, exactly as in already known versions; the slots 53 are specially designed to allow the circular section of the wall 51 to reduce when the spool B (Fig. 7) wound about the center undergoes treatments which cause shrinkage of the yarn and consequently a tightening of the turns of the spool B; what happens is that the wall 51 tends to reduce in diameter because of the ability of the slots 53 to reduce their transverse dimensions (as can be seen in Fig. thus easily resulting in this reduction of the diameter of said wall 51.

To prevent the problems discussed earlier, at the top end of the center, that is adjacent to the end 51A containing the step 52 on which another center can be stood, the cylindrical wall 51 includes an annular region of reduced thickness marked 55, the reduction in the thickness taking place on the exterior of the wall 51. The spool B is wound in such a way that the upper surface BX of the spool which corresponds to the surface BlB1 of the spool wound in the conventional arrangement illustrated in Fig. 2 is situated 00 approximately in the middle of said region 55 of S0 reduced thickness. On the outside said region 15 exhibits ribs 59 and indentations 59A between said ribs, the ribs 59 sloping from the outer surface 57 of 00 the wall 51 to the outer surface of the region 55 of smaller diameter. In line with the indentations 59A, in the reduced thickness of the region 55 there are 20 indentations 61 and 62 of approximately triangular 0S form; the indentations 61 terminate at the slot 53, while the indentations 62 are in line with the solid regions between two rows of slots 53 and extend at 62A into said region between these slots 53; the 25 indentations 61 and 62 are flanked by portions of material 65 which essentially constitute ribs equivalent to the ribs 59 and which extend between the region 55 of reduced thickness and the outer surface 57 of the wall 51.

In much the same way as described above, the bottom end 51B also comprises an annular region 155 of reduced thickness with ribs 159 and indentations 159A, as well as indentations 161 and 162 and ribs 165.

The ribs 59 and 65 (and the corresponding ribs 159, 165) defined in the above manner terminate practically in an intermediate position of the region (and 155) of reduced thickness that contains the boundary surface BX of the spool B which is formed with turns of yarn on the center. The result of this 6 arrangement is fundamental to preventing the formation of an outer region such as BIB1 defined above with reference to the conventional arrangement (Figs. 1, 2 and 6) of currently known centers and consequently the turns of the spool B formed on the center 51 of the invention are all identical in terms of their physical conditions of tensioning, when the spool B is subjected to the dyeing and other treatments that cause contraction of the yarn and a consequent deformation of the wall of the center. What happens, in the arrangement according to the invention, is that the regions 55 and 155 of reduced thickness deform evenly as shown in Figs. 7 and 10, when compared with the "conditions of the center and spool illustrated in Figs.

15 i, 2 and 6. The deformation takes place in practice as S shown in the cross section, Figs. 7 and 8, with the result that the reduction in diameter of the wall 51 extends in practice from the extremity BX of the spool B, as shown in Figs. 7 and 20 The presence of the ribs 59 and 65 ensures that the deformation in the region 55 of smaller thickness of the wall 51 occurs in a basically uniform manner without asymmetrical deformations, while the indentations 59A and 62, 62A enable the region 55 to 25 deform with a substantial reduction in its diameter corresponding to the reduction that takes place in the wall 51. The result is that the cross section of the center and therefore the configuration of the spool remain practically constant when the diameter reduces, as is required, from the top to the bottom of the spool.

At the lower end 51B of the spool B, it is advantageous to provide a series of indentations 71 (Figs. 3, 4, 5, 9 and 10) on which to accumulate a "reserve" of final turns of the yarn. The bottom rim BZ of the center may include an arrangement bearing the general reference 75 (Figs. 9 and 10) in which to anchor the end of the yarn of the spool by tearing a very thin portion 75A of the material of the center, which is split by the yarn being pushed into the entrance 75B, in an arrangement which has already been disclosed in an earlier intellectual property document referred to at the beginning of the description.

It will be understood that the drawing shows only an example of an embodiment purely as a practical demonstration of the invention, it being possible for said invention to be varied as regards its shapes and arrangements without thereby departing from the scope of the concept underlying the invention. The presence of any reference numerals in the appended claims is for the purpose of assisting the reading of the claims with reference to the description and drawing, and does not 0' «0 limit the scope of protection represented by the 15 claims.

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Claims (5)

1. An injection molded plastic cylinder for the dyeing of yarn, said cylinder adapted to receive a spool of yarn wound about it, and to subsequently have the yarn unwound from it, said cylinder includes a wall forming the outer surface of the cylinder, a plurality of rows of elongate slots each adjacent slot within a row being in spaced relation to an adjacent slot and adjacent rows being staggered so that the slot of one row is proximate an interstitial space between adjacent slots of an adjacent row, whereby on application of a uniform centripetal pressure to the wall by the winding of a spool of yarn, the cylinder undergoes a uniform reduction in circumference of said wall wherein the wall further includes a region of reduced circumference, said region including a plurality of indentations and ribs, said indentations and ribs in the annular region adapted to bring about a uniform reduction of circumference on application of the centripetal pressure.

2. The cylinder according to claim 1, wherein the indentations include a pair of aligned indentation portions.

3. The cylinder according to claim 1 or 2, wherein the indentations are aligned with the slots.

4. The cylinder according to claim 1, wherein the cylinder further includes a Sprofile adapted to retain one end of the spool of yarn. I:

5. An injection molded plastic cylinder as claimed in claim 1, substantially as hereinbefore described with reference to Figures 3 to 5, and 7 to S.i DATED this 1 9 th day of February 2002 ROMAGNOLI FABIA WATERMARK PATENT AND TRADE MARK ATTORNEYS LEVEL 21 77 ST GEORGES TERRACE PERTH WA 6000 AUSTRALIA