US3759024A

US3759024A - Method of and apparatus for imparting twist to yarns

Info

Publication number: US3759024A
Application number: US00148837A
Authority: US
Inventors: L Colton
Original assignee: Individual
Current assignee: Individual
Priority date: 1971-06-01
Filing date: 1971-06-01
Publication date: 1973-09-18
Anticipated expiration: 1990-09-18

Abstract

An apparatus for producing a plurality of pairs of matched yarns having identical twist characteristics in which yarns pass through a processing unit having heaters and twist heads. A composite twist head may be used which has a plurality of annular twisting components driven at the same speed from a common drive source. Alternatively, the twist head may have a single twisting component. The or each component receives one or more pairs of yarns, with the yarns in each pair travelling in respectively opposite directions through the component.

Description

United States Patent Colton 1 Sept. 18, 1973 METHOD OF AND APPARATUS FOR IMPARTING TWIST TO YARNS inventor:

Filed:

Lewis Henry Colton, 470 Mansfield Rd., Nottingham, England June 1, 1971 App]. No.: 148,837

US. Cl. 57/34 HS, 57/77.45, 57/157 TS Int. Cl. n01 1 /2s,po2 1/04 Field of Search ..57/77.3, 57/1, 77.45, 34 R,

57/34 HS, 157 TS, 157 MS References Cited UNITED STATES PATENTS 6/1969 11/1970 10/1971 1l/l97l MacKintosh 57/77.45 X MacKintosh.... 57/77.4

Peel 66/125 A Wyatt 66/125 A X MacKintosh 57/77.45 X

3,066,473 12/1962 Maeda ..57/77.4

Primary Examiner-Donald E. Watkins Attorney-Holman & Stern [57] ABSTRACT An apparatus for producing a plurality of pairs of matched yarns having identical twist characteristics in which yarns pass through a processing unit having heaters and twist heads.

A composite twist head may be used which has a plurality of annular twisting components driven at the same speed from a common drive source. Alternatively, the twist head may have a single twisting component. The or each component receives one or more pairs of yarns, with the yarns in each pair travelling in respectively opposite directions through the component.

7 Claims, 6 Drawing Figures Patented Sept. 18, 1973 3,759,024

5 Sheets-Sheet 1 TZY'N Patented Sept. 18, 1973 I 3,759,024

5 Sheets-Sheet 3 Patented Sept. 18, 1973 5 Sheets-Sheet 4.

Patented Sept. 18, 1973 3,759,024,

5 Sheets-Sheet 5 "FIG. 6

METHOD OF AND APPARATUS FOR IMPARTING TWIST TO YARNS BACKGROUND OF THE INVENTION This invention relates to the twisting of yarns.

Primarily, although not exclusively, it is concerned with the false twisting of continuous, multi-filament, thermoplastic yarns.

PRIOR ART In conventional false twisting apparatus, synthetic yarn is twisted to the extent ofa relatively large number of turns per inch and is heat set. By a relatively large number of turns is, for example, meant any appropriate number in the range from 80 120 per inch; thus a yarn of, say 20 'deniers would have imparted thereto about I turns per inch. In any event, the twisting and heat setting of the yarn results in its bulking up and becoming lively upon subsequent recovery. A false twisted yarn is accordingly a stretch yarn suitable for the production of stretchable fabrics and hosiery, e.g. stockings and tights.

One conventional method of imparting twist to yarn employs a twist head comprising a driven, rotary, annular component with the yarn being caused to roll over the inner surface of the component so that it is frictionally twisted about its longitudinal axis. The component may, for example, have trumpet-shaped ends to allow two yarns to be simultaneously passed therethrough in opposite directions. In this way, the two yarns are simultaneously twisted so that respectively opposite handed twist is imported thereto, i.e. receive an S" and "2 twist.

A conventional yarn processing apparatus employs a plurality of these twist heads arranged at spaced positions along a yarn path with heaters interposed therebetween so that the yarn travels successively through the heads and over the heaters. However, even where the heads have trumpet-shaped ends as mentioned above, hitherto a maximum of two yarns only can be simultaneously processed. This is manifestly a severe limitation on the productivity of the apparatus.

An apparatus of this kind may be used to process yarns in the course of their delivery to a knitting or other textile machine. In this event, the limitation to a maximum of twoyams restricts the range of application of the apparatus to twin feed machines only. To cater for machines having a greater number offeeds, it has been necessary to provide additional sets of apparatus, each comprising a set of twist heads and associated heaters. For example, the apparatus must be duplicated for a four feed machine.

Apart from increasing the cost, duplication of the apparatus has the disadvantage that the yarns may not all be processed under the same condition in all the sets of apparatus, with the result that they exhibit different characteristics so that the fabric knitted by the machine is not uniform.

OBJECTS AND SUMMARY OF THE INVENTION yarns, comprising a plurality of twist heads through a which the yarn pairs successively pass in travelling therethrough, and heaters along which the twisted yarns are heated, with each twist head having one or more rotary annular components through which the pairs of yarns are passed so as to be twisted by frictional contact with their inner surfaces, the yarns in the or each pair travelling in opposite directions through the same component so that respectively opposite handed twist is imparted thereto.

As will be appreciated, the invention will greatly increase the productivity of a yarn twisting apparatus without substantially increasing its initial cost. The advantages derived from the invention will be particularly significant in a yarn processing apparatus associated with a knitting machine. In this case, a single set of twist heads can be provided to produce a plurality of pairs of identically matched yarns, thereby ensuring uniformity in the knitted fabric produced from the yarns.

According to one embodiment of the invention, a plurality of pairs of yarns may be passed through the or each rotary twisting component of each twist head in the apparatus, and yarn guiding means are provided in association with the head to maintain the yarns at an angular spacing from one another, both on entering and on leaving the component.

In another embodiment, each twist head may comprise a plurality of rotary annular components, through each of which can be passed pairs of yarns travelling in opposite directions, and means to enable the components to be rotated at the same speeds from a common drive source so as to twist the pairs of yarns under the same conditions.

In this latter situation, it is possible to incorporate the common drive source for the rotary twisting components in the twist head itself. For example, an electric or fluid motor could be used with appropriate transmission means (e.g. gearing) between the motor and the components. Preferably however, belt drive means are employed.

Thus, each rotary component in the head preferably carries a coaxial pulley by which it can be driven in rotation, and all the pulleys in the head are identical so that the components can be driven at the same speed from a common drive source.

These pulleys are belt driven from a main driving pulley or pulleys externally of the head. Normally, the driving pulley(s) will be incorporated in yarn processing apparatus to which the head is fitted, with the belts driving the twisting components being connected after the head has been fitted to the unit.

The drive from the driving pulley(s) may be direct or via an intermediate shaft. In this case, the twisting components are mounted for rotation about a common axis and the intermediate shaft is mounted with its axis parallel to said common axis, and this shaft is adapted to be driven from an external drive source and carries a plurality of identical pulleys, each of which is associ ated with one of the component-driving pulleys and is arranged to drive its associatd pulley through a belt.

Preferably, each rotary twisting component has a relatively small central opening which extends axially of the component and merges into trumpet-shaped ends thereof, each said end having an outwardly flared convex surface of annular form and being provided with an initially separate ring which is set in an annular groove in said surface, is raised slightly from the general curve of the latter, and is of a friction-engendering material so that yarns travelling through the head are engaged and twisted primarily by contact with said rings;

The invention has been found most useful in connection with the production of stockings, pantyhose (sometimes called tights) and similar garments in which it is important for the yarns from which the garment is knitted to be perfectly matched to ensure uniformity in the finished garment. The invention therefore includes within its scope a garment of this kind produced by the invention.

To facilitate understanding of theinvention, and to enable it to be readily carried into practice, reference will now be made to the accompanying drawings which illustrate two embodiments thereof, by way of example, and in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a yarn processing unit constructed according to the invention, which is associated with a knitting machine,

FIG. 2 is a vertical sectional view through a twist head of the form employed in the processing unit of FIG. 1,

FIG. 3 is a diagrammatic perspective illustration, showing the paths followed by the yarns in the unit of FIG. 1,

FIG. 4 is a view of part of a processing unit of the kind shown in FIG. 1, to illustrate a different embodiment of the invention,

FIG. 5 is a somewhat diagrammatic view in the direction of arrow A in FIG. 4, with the twist head shown partly in section and its casing indicated in chain lines for clarity, and

FIG. 6 is a diagrammatic side view of a twist head/- heater assembly according to a further aspect of the invention. Like references denote like parts throughout the drawings.

DETAILED DESCRIPTION OF THE DRAWINGS Referring first to FIG. 1, the drawings show a processing unit P carried by a vertical shaft S which projects upwardly from a four-feed circular knitting machine K of conventional form. Shaft S also carries a number of bobbins B of continuous, multi-filament, thermoplastic yarns to be delivered to the machine K. Thus, the yarns travel upwards from the bobbins B to the unit P in which they are processed before being delivered to the machine K for knitting.

Unit P comprises a frame. (for the sake of clarity indicated as a triangular base :1) which carries a plurality of twist heads T, a compensator C and heaters H. Three of the twist heads, T1, T2 and T3 are positioned one at each comer of base 1 with the heaters on the sloping sides of the base. On the horizontal side of the base is the remaining twist head. T4, arranged adjacent twist head T3, and the compensator C adjacent twist head T1. i

Each twist head T isdriven by a belt system from a flexible drive shaft 2, and the shaft 2 is driven from the main drive shaft; of the machine K. The speed of the shaft 2 is correlated with that of the machine by a pair Shaft 2 is connected inunit P to a pair of toothed pul leys 6 (one of which is visible) arranged side by' side andmounted on the frame of the unit. One of the pulleys 6 drives a main toothed belt 7 which follows a generally triangular path around the frame 1 and is guided by further multiple

toothed pulleys

8a, 8b, 8c and 8d and by a single jockey pulley 9.

Oneof the pulley wheels on each of the multiple pulleys 8a to 8d guides the main belt 7, while the'other is employed to drive the component of the apparatus associated therewith (i.e. a twist head T or, in the case of pulley 8d, the compensator C) through an auxiliary belt 10.

Before referring to FIG. 2 to explain the construction of the twist heads T, brief reference will be made to the compensator C. It comprises a casing 11 which is mounted on the frame 6 of the unit and carries a pair of horizontal parallel shafts 12 which project from opposite sides of the casing 11. The projecting parts of each shaft carry a pair of pulleys 13 around which the yarns pass on entering or leaving the unit. Thus, the pulleys on the shaft 12 at the right hand side of the compensator in FIG. I carry the yarns as they enter the unit P, the yarns, as they leave the unit, being passed around the pulleys on the left hand shaft 12. The speed at which the shafts 12 are driven is selected to impart exactly the required drive speed to the yarns both on entering and on leaving the unit P.

Reference will now be made to FIG. 2 which illustrates one of the twist heads T1 or T2 of FIG. 1. The other two twist heads are basically of similar construction; the differences from the FIG. 2 arrangement will be referred to later. J

Twist head T comprises a hollow casing 14 which is arranged to be mounted at its lower end on the frame 6 of unit P. This casing defines a pair of identicalupstanding housings 15, each of which carries a rotary annular twisting component 16. Each of the components comprises a pair of co-axially disposed elements 17 arranged in opposed positions and rigidly connected by a bushing 18. Each element 17 is generally trumpetshaped and carries an inset ring 17a of a frictionengendering material (e.g. a ceramic) by which yarns travelling through the component are engaged and twisted as the latter rotates.

The bushing 18 carries the inner race of a ball bearing 19, and the outer race thereof is mounted in the casing 14 of the head. Alongside the inner race of bearing 19, the bushing 18 carries a toothed wheel 20 by which the component 16 is driven in rotation in use. Wheel 20 is itself driven by a belt 21 formed with teeth complementary to those'on the wheel. It will be appreciated that the component 16 in the housing 15 at the right hand side of FIG. 2 is of identical construction tothat which has just been described and is driven by a similar toothed belt 21. Each of these belts extend around the toothed pulley 22 on a common shaft 23 mounted parallel to the two components 16 in bearings in FIG. 1.

As-will be appreciated from the foregoing description, the twist head shown in FIG. 2 is adapted, in this embodiment, to process two pairs of yarns, one in each component 16, with the yarns in each pair being passed in opposite directions through the relevant component 16 so as to have a respectively opposite handed twist imparted thereto. Thus, each of the components produces one S and one 2 twist yarn. It is however,'to be understood that more than one pair of yarns may be passed through each component 16 within the scope of the invention as will be explained later. In the present embodiment, since both of the components 16 are identical and since they are driven at identical speeds, the two pairs of yarns processed by the head will be perfectly matched, having been processed under identical conditions.

The twist head T3 at the bottom left hand corner of the processing unit P in FIG. 1 is identical with the head of FIG. 2 except that the intermediate shaft 23 (FIG. 2) in the casing 14 is omitted from the twist head, and the belts 21 driving the components 16 are driven directly from the pulley assembly 8b associated with that head. Thus, this assembly is, in fact, a triple pulley assembly, with one pulley being driven by the main belt 7 and the other two pulleys driving the belts 21 of the twist head. Moreover, each of the belts 21 is twisted between the pulley assembly 8b and the driving wheel on the relevant component 16 so that the two components 16 are driven in opposite direction to the components 16 in the other twist heads. This arrangement of driving one twist head in the reverse direction is found, in practice, to produce the most advantageous processing conditions.

The final twist head T4 at the bottom of the frame 6 of the unit is identical with twist head T3 (i.e. the intermediate shaft 23 of FIG. 2 in omitted) except that there is no reversal of the drive; in other words, the belts 21 are not twisted between the head and the associated pulley assembly 8c.

FIG. 3 is a diagrammatic illustration showing the paths of the yarn through the twist heads in the unit of FIG. 1. Four yarns arranged in two pairs Y1 and Y2 enter the unit via the compensator C. From here, each pair travels through relevant rotary components 16 of the twist head T1 at the bottom right hand corner of the unit, over the right hand heater H (the heaters have been omitted from FIG. 3 for clarity) through the twist head T2 at the top of the unit, over the other heater I-I, through the twist head T3 at the bottom left hand corner of the unit (driven in opposite direction to the other twist head), through the twist head T4 at the bottom of the unit and back to the compensator C before being delivered to the machine. As will be appreciated, the yarns in each pair follow identical paths and are twisted under identical conditions so that, on leaving the unit, two pairs of perfectly matched yarns have been produced. This ensures uniformity and evenness in the fabric into which the yarns are knitted.

As will be appreciated, by increasing the number of coaxial rotary components 16 in each twist head and correspondingly increasing the width of the heaters, an even greater number of pairs of yarns may be processed under identical conditions in accordance with the invention. For example, by doubling the size of each twist head compared with the FIG. 2 arrangement, four pairs of matched yarns may be produced in a single processing unit.

FIGS. 4 and 5 illustrate a different embodiment of the invention.

FIG. 4 shows part of a yarn processing apparatus similar to that shown in FIG. 1 and comprises a base frame 1 which is of triangular shape and has a twist head T mounted at each corner thereof. In this embodiment, the twist heads T are similar to those shown in FIGS.

Thus, the yarns Y1, Y2 of one pair enter respectivelyopposite sides of the twisting component 16 straight from the heater H. The other pair Y3, Y4 travel parallel to the yarns Y1, Y2 over the heater H but, before reaching the twist head, are each deflected by a guide G so as to enter the twist head, at an angular spacing to the corresponding yarn Y1 or Y2 in the other pair. Similarly, on leaving the twist head, the yarns Y3, Y4 pass through guides G which deflect the yarns back into the same path as the yarns Y1. As can be seen from FIG. 5, the guides G are arranged so that each yarn Y is drawn closely into contact with the inset rings 17a and travels in contact with the surface of component 17 on each side of each of the rings. This ensures that a positive frictional twist is imparted to the yarn.

It will be appreciated that, within the scope of the invention, it would be possible to simultaneously pass more than two pairs of yarns through a single rotary component so long as the yarns are separated by appropriate guides at opposite sides of the component.

Moreover, in a twist head of the form illustrated in FIG. 2 having two or more rotary annular components, a plurality of pairs of yarns can be passed through each component, For example, (as indicated at DT in FIG. 5) a double twist head can be employed, with a correspondingly wider heater. Each rotary component then receives and twists two pairs of yarns, thereby enabling four pairs of identically matched yarns to be produced by the processing unit. Of course, by increasing the number of pairs of yarns twisted by each component, the scope of the processing unit can be increased even more.

In this way, it is possible to widen the scope of application of the invention even further. For example, a processing apparatus constructed according to the invention may be adapted to feed yarn to a multi-feed (i.e. large diameter) machine (e.g. an interlock or single or double jerseymachine).

In this event, packages of flat, i.e. unprocessed, yarn carried on a creel may befed to the machine through a processing unit in accordance with the method of the invention. The large number of yarns required by such a machine can be processed using a relatively small number of twist heads by simultaneously passing a large number of pairs of yarns through each head using guides as shown in principle by FIGS. 4 and 5.

The processing unit may be mounted intermediate the creel and machine and feed yarn to the latter through a distributor head on top of the machine.

A second example of an application of the invention is in the preparation of warp beams. FIG. 6 illustrates diagrammatically a part of a processing unit constructed according to the invention for this purpose.

The drawing shows a twist head T, of similar construction to that illustrated in FIGS. 4 and 5, arranged with its axis of rotation horizontal. At each side of the head is a yarn guide 26 comprising a horizontally directed comb 27 having five teeth 28 on each of which is mounted a tube 29 by which the yarns are guided. Each comb shown has an identical partner (not visible) with its teeth directed in the opposite direction.

The pair of combs 28 at the left hand side of FIG. 6 guide to the twist head, five pairs of flat yarns delivered thereto from a creel (not shown), with the yarns in each pair passing through the head in opposite direction. The other pair of combs guide the yarns leaving the head over a common heater H having its heating surface disposed in a vertical plane. From here, the yarns may pass through further twist heads and over further heaters according to the desired twist characteristics to be imparted thereto, before being wound onto the warp beam.

The vertical positioning of the heaters H enables further similar twist head/heater assemblies to be grouped side by side in a minimum space. Thus, in the case of a warp beam carrying 500 yarns, it would be necessary to provide 50 side-by-side assemblies of the kind shown in FIG. 6 each processing 10 yarns.

Of course, the heater H could, if convenient, be mounted at any other angle.

In any twisting apparatus of the kind with which the invention is concerned, it is thought that the yarns must be deflected to a minimum extent while they are actually being twisted, but that there is no limitation on the amount of deflection which can be employed afterwards.

I claim:

1. Apparatus for producing a plurality of pairs of matched, processed yarns having identical twist characteristics, comprising a plurality of twist heads through which the yarns pairs successively pass in travelling through the apparatus, and heaters along which the twisted yarns are heated, each twist head comprising a plurality of rotary annular components, through each of which can be passed pairs of yarns travelling in opposite directions so that respective opposite handed twist is imparted thereto by frictional contact with their inner surfaces, and means to enable the components to be rotated at the same speeds from a common drive source so as to twist the pairs of yarns under the same conditions.

2. Apparatus according to claim 1, wherein each rotary component in the head carries a co-axial pulley by which it can be driven in rotation, all the pulleys in the head being identical so that the components can be driven at the same speed from a common drive source.

3. Apparatus according to claim 2, wherein the rotary twisting components are mounted for rotation about a common axis, and wherein an intermediate drive shaft is provided in the head with its axis parallel to said common axis, said shaft being adapted to be driven from an external drive source and carrying a plurality of identical pulleys, each of which is associated with one of the component-driving pulleys and is arrangedto drive its associated pulley through a belt. .4. Apparatus according to claim 3, wherein the intermediate drive shaft carries a pulley by which it can be driven from an external drive pulley through a belt.

5. Apparatus for producing a plurality of pairs of matched, processed yarns having identical twist characteristics comprising a plurality of twist heads through which the yarn pairs successively pass in travelling through the apparatus, and heaters along which the twisted yarns are heated, each twist head including at least one rotary annular component through which the pairs of yarns are passed so as to be twisted by frictional contact with their inner surfaces, the yarns in each pair travelling in opposite directions through the same component so that respectively opposite handed twist is imparted thereto, each rotary twisting component having a relatively small central opening which extends axially of the component and merges into trumpet-shaped ends thereof, each said end having an outwardly flared convex surface of annular form and being provided with an initially spearate ring which is set in an annular groove in said surface, is raised slightly from the general curve of the latter, and is of a friction-engendering material so that yarns travelling through the head are engaged and twisted primarily by contact with said rings.

6. Apparatus for producing a plurality of pairs of matched, processed yarns having identical twist characteristics, comprising a plurality of twist heads through which the yarn pairs successively pass in travelling through the apparatus, and heaters along which the twisted yarns are heated, each twist head including at least one rotary annular component through which the pairs of yarns are passed so as to be twisted by frictional contact with their inner surfaces, the yarns in each pair travelling in oppsoite directions through the same component so that respectively opposite handed twist is imparted thereto, said apparatus being intimately associated with a knitting or other textile machine and including a plurality of pulley assemblies which are associated one with each twist head and from which the rotary components in the twist heads are driven by belts, said assemblies themselves being driven at a speed correlated to that of the machine.

7. Apparatus according to claim 6, wherein a common drive belt drivably engages each of the pulley assembliesand it itself driven from the knitting or other textile machine by a flexible drive shaft so that the speed at which the common drive belt is driven and hence the speed of the rotary twisting components in the twist heads varies with the speed of the machine.

a t i 8 I

Claims

3. Apparatus according to claim 2, wherein the rotary twisting components are mounted for rotation about a common axis, and wherein an intermediate drive shaft is provided in the head with its axis parallel to said common axis, said shaft being adapted to bE driven from an external drive source and carrying a plurality of identical pulleys, each of which is associated with one of the component-driving pulleys and is arranged to drive its associated pulley through a belt.

4. Apparatus according to claim 3, wherein the intermediate drive shaft carries a pulley by which it can be driven from an external drive pulley through a belt.

7. Apparatus according to claim 6, wherein a common drive belt drivably engages each of the pulley assemblies and it itself driven from the knitting or other textile machine by a flexible drive shaft so that the speed at which the common drive belt is driven and hence the speed of the rotary twisting components in the twist heads varies with the speed of the machine.