NZ336048A - Winding a smooth finish wool yarn - Google Patents

Abstract

Three or more slivers of wool or predominantly wool 1, 2, 3 are passed through a single reciprocating twisting stage 6 to be simultaneously twisted into strands each having areas of twist separated by areas of no twist. The strands are then brought together to form a yarn via eyelet 7, one of the strands being diverted via eyelet 8 so that the areas of twist 3a of the strand 3 taking the longer path overlays the areas of non-twist 1a, 2a in the other strands of the finished yarn.

Description

121127 PATENTS FORM 5 Number 336048 PATENTS ACT 1953 Dated 31 May 1999 COMPLETE SPECIFICATION METHOD FOR PRODUCING A YARN We, LANDSDOWN RUN CORPORATION LIMITED, a New Zealand company, of 177 Maces Road, Christchurch, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to 35 us, and the method by which it is to be performed, to be particularly described in and by the following statement.

INTELLECTUAL PROPERTY OFFICE OF N.Z. - 9 jun 2000 received 121127 FIELD The invention comprises a wool yarn or a yarn formed predominantly of wool, and a method and apparatus for producing the yarn.

BACKGROUND In producing a wool yarn or a yarn which is formed predominantly of wool, a number of wool slivers may, typically after drafting, be passed through a twisting stage which 10 comprises one or more reciprocating rollers which move from side to side as the wool slivers pass between the rollers thereby imparting a twist to the strands. After exiting the twisting rollers the strands are brought together with a further twist, to form the yam.

SUMMARY OF INVENTION The patent invention provides an improved or at least alternative method and apparatus for producing a yam and an improved yam.

In broad terms in one aspect the invention comprises a method for producing a yam of wool or predominantly of wool, comprising passing three or more slivers of wool or predominantly of wool through a single reciprocating twisting stage to produce three or more twisted strands each having areas of twist separated by areas of non-twist, and bringing all of the strands together after passing one or more of the strands over 25 a longer path so that areas of twist in the one or more strands which pass over a longer path overlay areas of non-twist in the other strand(s) in the finished yam.

In broad terms in another aspect the invention comprises apparatus for producing a yam of wool or predominantly of wool, comprising a single reciprocating twisting 30 stage adapted to simultaneously twist three or more slivers of wool or predominantly of wool to produce three or more twisted strands each having areas of twist separated by areas of non-twist, a first guide positioned such that one or more of the strands pass(es) from the reciprocating twisting stage over a path of similar length and through said first guide, and a second guide positioned relative to the first guide 35 and the reciprocating twisting stage such that one or more other(s) of the strands pass(es) over a longer path through said second guide and then through said first INTELLECTUAL PROPERTY OFFICE 2 OF N.Z. - 9 jun 2000 received 121127 guide so that in use areas of twist in the one or more strands which pass over a longer path will overlay areas of non-twist in the other strand(s) in the finished yarn.

The method and apparatus of the invention produces a yarn from a reciprocating 5 twisting stage in which there are substantially no areas of non-twist or "flat spots" in the finished yarn as can be the case with yarn formed through a reciprocating twisting stage, because the areas of non-twist in one or more strands of the yam are overlaid by areas of twist in one or more other strands of the yam. Rather than all of the yam strands passing through the twisting stage together and then being brought together, 10 in the invention one or more of the strands is staggered or delayed relative to one or more of the other strands so that in the finished yam the areas of non-twist in one or more strands of the yam are overlaid by areas of twist in one or more other strands. The yam has improved quality.

BRIEF DESCRIPTION OF THE DRAWINGS I The method and yam of the invention are further described with reference to the accompanying drawings by way of example and without intending to be limiting, wherein: Figure 1 is a view of a length of the yam produced by the method of the invention, Figure 2 schematically shows the stages in producing the yam of the invention, Figure 3 is a close up view of one preferred form of apparatus for producing the yam of the invention showing the drafting unit and twisting rollers thereof, and Figure 4 shows the strands exiting the twisting rollers being brought together by eyelets, in the preferred form apparatus of Figure 3.

DETAILED DESCRIPTION OF PREFERRED FORM Referring to Figure 1 the yam illustrated comprises three twisted strands which Eire loosely twisted together to form the finished yam. Strand 3 is "staggered" relative to 35 strands 1 and 2, so that the areas of twist 3a in strand 3 align with the areas of non-twist la/2a in strands 1 and 2 as shown. Figure 1 exaggerates this for clarity. In the INTELLECTUAL PROPERTY OFFICE OF N.Z. - 9 jun 2000 received 121127 finished yarn the areas of non-twist in strands 1 and 2 are overlaid by areas of twist in strand 3 so that the finished yarn does not comprise "flat spots" or significant areas of non-twist in the finished yarn.

Figure 2 schematically shows the steps in production of the yarn in one preferred form. The preferred form apparatus comprises a conventional drafting unit 5 comprising opposed moving rubber belts between which the fibres pass. Three wool slivers (unspun) drawn from drums or other bulk supply (not shown) are fed between rollers 4 and through the drafting unit 5 and are drawn out - typically the thickness of 10 the wool fibre assembly is reduced to one half to one 25th of the initial thickness. The amount of thickness reduction may be adjusted by altering the speed of the drafting units.

The apparatus comprises a single reciprocating twisting stage which is a reciprocating 15 twist roller 6 formed by a pair of rollers 6a and 6b, one or both of which as well sis rotating reciprocates back and forth across the direction of movement of the strands as the apparatus operates. The twist rollers 6 thus impart twist in one direction as the roller(s) move(s) one way followed by a twist in another direction as the roller(s) move(s) the other way in operation. In addition there can tend to be an area of non-twist in the 20 strands or each of them at the point at which the roller changes direction.

Two of the strands are led through guide or eyelet 7 such that these two strands follow a path of similar distance to each other, while the third strand is led through guide or eyelet 8 which is so positioned that the third strand passes over a path of 25 predetermined longer distance, before entering the eyelet 7. As the three strands exit the eyelet 7 they tend to self twist together or alternatively a further twisting mechanism may optionally be provided to assist in twisting the three strands together, to form the finished yarn.

The length of the longer path over which the third strand passes, through eyelet 8, is such that the areas of non-twist in the third strand do not align with the areas of non-twist in the first two strands. The areas of twist in the third strand overlay the areas of non-twist in the first two strands in the finished yarn.

Figures 3 and 4 show one preferred form apparatus for forming the yarn of the invention in more detail. In these figures the same reference numerals as in Figure 2 4 INTELLECTUAL PROPERTY OFFICE OF N.Z. - 9 jun 2000 received 121127 indicate the same components, ie the roller 4, drafting unit 5, twist roller 6 and exit eyelets 7 and 8.

The foregoing describes the production of yarn from three strands but alternatively 5 four strands may be brought together in an arrangement whereby one or more strands are staggered relative to one or more other strands such that the areas of twist in one or more strands overlay areas of non-twist or one or more other stands.

The foregoing description and drawings illustrate one possible apparatus for forming 10 the yarn of the invention by the method of the invention and other arrangements may be possible which achieve a multi-stranded yarn formed with a reciprocating twist stage in which some strands of the yarn are staggered relative to other strands when the strands are brought together to form the yarn, such that areas of twist in one or more strands overlay areas of non-twist in one or more other strands.

The foregoing describes the invention including a preferred form thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be incorporated within the scope hereof as defined in the following claims.

INTELLECTUAL PROPERTY OFICE OF N.Z. - 9 jun 2000 received 121127

Claims (14)

CLAIMS:

1. A method for producing a yarn of wool or predominantly of wool, comprising passing three or more slivers of wool or predominantly of wool through a single 5 reciprocating twisting stage to produce three or more twisted strands each having areas of twist separated by areas of non-twist, and bringing all of the strands together after passing one or more of the strands over a longer path so that areas of twist in the one or more strands which pass over a longer path overlay areas of non-twist in the other strand(s) in the finished yarn. 10

2. A method according to claim 1 wherein the reciprocating twisting stage comprises a pair of rollers, at least one of which is arranged to move back and forth along its axis of rotation relative to the other as the slivers pass between the rollers. 15

3. A method according to claim 1 wherein the reciprocating twisting stage comprises a pair of rollers, each of which is arranged to move back and forth along its axis of rotation relative to the other as the slivers pass between the rollers.

4. A method according to any one of claims 1 to 3 including passing the slivers 20 through a drafting stage prior to passing the slivers through the reciprocating twisting stage.

5. A method according to claim 4 wherein in said drafting stage the thickness of each sliver is reduced to between one half to one twenty fifth of its thickness prior 25 to drafting.

6. A method according to any one of claims 1 to 5 wherein the step of bringing all of the strands together after passing one or more of the twisted strands over a longer path comprises causing one or more of the strands to pass from the 30 reciprocating twisting stage over a path of similar length and through one guide and causing one or more other(s) of the strands to pass over a longer path from the reciprocating twisting stage, through another guide spaced from the first guide, and then through the first guide, and allowing all of the strands to naturally twist together after passing through the first guide. 35 6 INTELLECTUAL PROPERTY OFFICE OF N.Z. - 9 jun 2000 received 121127

7. A method according to any one of claims 1 to 6 wherein the slivers are slivers of unspun wool.

8. A method of producing a yarn of wool or predominantly of wool, substantially 5 as herein described with reference to the accompanying drawings.

9. A yarn produced by the method of any one of claims 1 to 8.

10. Apparatus for producing a yarn of wool or predominantly of wool, comprising 10 a single reciprocating twisting stage adapted to simultaneously twist three or more slivers of wool or predominantly of wool to produce three or more twisted strands each having areas of twist separated by areas of non-twist, a first guide positioned such that one or more of the strands pass(es) from the reciprocating twisting stage over a path of similar length and through said first guide, and a second guide 15 positioned relative to the first guide and the reciprocating twisting stage such that one or more other(s) of the strands pass(es) over a longer path through said second guide and then through said first guide so that in use areas of twist in the one or more strands which pass over a longer path will overlay areas of non-twist in the other strand(s) in the finished yarn. 20

11. Apparatus method according to claim 10 wherein the reciprocating twisting stage comprises a pair of rollers, at least one of which is arranged to move back and forth along its axis of rotation relative to the other as the slivers pass between the rollers. 25

12. Apparatus according to claim 10 wherein the reciprocating twisting stage comprises a pair of rollers, each of which is arranged to move back and forth along its axis of rotation relative to the other as the slivers pass between the rollers. 30

13. Apparatus according to any one of claims 10 to 12 including a drafting stage prior to the reciprocating twisting stage.

14. Apparatus for producing a yarn of wool or predominantly of wool, substantially as herein described with reference to the accompanying drawings. 35 WEST-WALKER BENNETT per ATTORNEYS FOR THE APPLICANT INTELLECTUAL PROPERTY OFFICE OF NZ - 9 jun 2000 received