GB2070082A

GB2070082A - Apparatus for Producing Fancy Yarns

Info

Publication number: GB2070082A
Application number: GB8103855A
Authority: GB
Original assignee: Saurer Allma GmbH
Current assignee: Saurer Allma GmbH
Priority date: 1980-02-23
Filing date: 1981-02-09
Publication date: 1981-09-03
Also published as: DE3006863C2; DE3006863A1; FR2476692A1; GB2070082B; JPS56128319A; FR2476692B3

Abstract

An effect-forming yarn E and two ground threads G1 and G2 are combined and false-twisted downstream of the driven delivery roller 2a and the press roller 2b, using a rotating hollow spindle 7a which carries a bobbin of binding thread B and has a twist limiter at its downstream end. A fixed thread guide 13 defined between legs 13a and 13b is provided at one end of the press roller 2b for the ground thread G1 and a similar guide at the other end of the roller for G2. The guides 13 which are adjustable in the thread-running direction and perpendicular to the thread-running plane, lie close to the line of contact L between the rollers 2a and 2b and thus substantially in the thread running plane e-e which contains the line of contact L and the yarn components E, G1 and G2 downstream of the rollers. The axial length of press roller 2b is preferably less than its diameter. <IMAGE>

Description

SPECIFICATION Apparatus for Producing Fancy Yarn The invention relates to an apparatus for producing fancy yarn, comprising at least one pair of delivery rollers for feeding an effect-forming yarn component, which pair of rollers consists of a driven delivery roller and a press roller pressed against said roller, a device for feeding a ground thread, a hollow spindle which carries a binding thread bobbin and comprises a twist limiter, and a pair of draw-off rolls.

In this known type of apparatus for producing fancy yarn (German Offenlegungsschrift 2,439,732), the effect-forming yarn component and the ground thread are guided together through the pair of delivery rollers. Separate brakes for the effectforming yarn component and for the ground thread make it possible for the two yarn components to run through the pair of delivery rollers at different speeds. The delivery speed for the effect-forming yarn component is usually higher and is determined by the speed of the delivery rollers. The ground thread is retarded by a stronger braking action and its speed is substantially determined by the draw-off rolls.

Since the delivery rollers rotate at a speed which is higher than that of the ground thread, slippage occurs between the latter and the delivery rollers and gives rise to rapid wear on the surfaces of the pair of delivery rollers. Undesirable grooves are formed in the surface. Moreover, the slippage results in abrasion on the ground thread, giving rise to soiling of the machine. In addition, the known apparatus only allows a limited number of effects to be produced. Also, the evenness of the fancy yarn leaves much to be desired, particularly when the apparatus is set in operation after elimination of a fault. Moreover, it is impossible to use the known apparatus to produce flame effects or twist effects having an exact colour sequence.

As a result of the grooves formed in the delivery rollers, the excess delivery becomes uncontrollable, i.e. the difference in speed at which the effect-forming yarn component is fed to the ground thread.

The object underlying the invention is to provide an apparatus for producing fancy yarn of the type mentioned in the introduction, in which wear on the pair of delivery rollers is virtually eliminated, and the abrasion of the ground thread is largely avoided and which, moreover, makes it possible to produce an even fancy yarn having a greater number of possible variations.

This is achieved in accordance with the invention in that on at least one end of the press roller in the vicinity of the line of contact of the delivery roller and press roller, a fixed thread guide for the ground thread is arranged substantially in the thread running plane passing through the line of contact and through the yarn components which are combined and falsetwisted after the line of contact.

The arrangement of the said thread guide, which is located laterally of the face of the press roller, makes it possible for the ground thread to be guided past laterally of the gap formed between the two rollers. As the ground thread is no longer in contact with the pair of delivery rollers delivering the fancy yarn component, wear on the said pair of delivery rollers and at the same time also abrasion of the ground thread and therefore soiling of the machine are avoided.

Moreover, the point at which the ground thread and fancy yarn component are combined is determined to some extent by the thread guide, but this point at which the threads are combined lies downstream of the gap between the rollers, i.e. downstream of the line of contact between the pair of delivery rollers and, in the thread running direction, also downstream of the thread guide. Depending on the respective thread tensions, this combination point can move in the thread running direction, thereby improving the evenness of the fancy yarn. Moreover, by adjusting the thread guide, particularly in the thread running direction, the point at which the ground thread and fancy yarn component are combined can be adjusted, whereby the apparatus can be better adapted to the respective twisting conditions which occur as a result of different rotational speed, delivery speed and thread tension.This also affords a greater opportunity for varying the effects to be produced.

Different effects can also be produced by this means, depending on the end of the press roller at which the thread guide is located.

Therefore, a thread guide is advantageously arranged at each end of the press roller. The said two thread guides allow not only feeding of the ground thread to the fancy yarn component from one side or the other, but also the simultaneous feeding of two ground threads to the fancy yarn component from two different sides.

Further advantageous embodiments of the invention emerge from the remaining subsidiary claims.

The invention is described in more detail below with the aid of an exemplary embodiment illustrated in the drawing.

In the drawing Fig. 1 shows a side view of the apparatus, Fig. 2 shows a plan view in a direction II of Fig.

1, Fig. 3 shows a diagrammatic view of the pair of delivery rollers having two thread guides for the ground threads, and Fig. 4 shows a side view of this arrangement.

A relatively large number of the apparatuses according to the invention are mounted side by side in the machine frame 1; the construction and function of one of these apparatuses is described below. The apparatus comprises firstly a pair of delivery rollers 2, consisting of a continuous driven delivery roller 2a and a press roller 2b which is relatively narrow in the axial direction.

The said roller is mounted on a press roller carrier 3 and is pressed flexibly against the driven delivery roller 2a via means which are known per se and are not shown in detail. Since the fancy yarn component E can consist of one roving or a plurality of rovings, a drawing mechanism having a driven centre roll 4 and a back roll 5 is also provided in advance of, that is to say, upstream of, the pair of delivery rollers 2. The speed ratio of the back roll 4 to the centre roll 5 can be varied by a multi-step reduction gear, whilst the speed ratio of the pair of delivery rollers 2 to the back and centre rolls 4, 5 is infinitely variable. In addition, a separate pair of delivery rollers 6, which again also consist of a continuous delivery roller 6a and a press roller 6b, are provided for feeding one or a plurality of ground threads G1, G2.

Rotatably mounted in the machine frame 1, after, that is to say, downstream of, the pair of delivery rollers 2, is a hollow spindle 7 which is driven on the whorl 8 by a tangential belt 9. The hollow spindle 7 carries a binding thread bobbin 10 which rotates with the hollow spindle 7. The binding thread B is drawn off the binding thread bobbin 10 and guided into the upper end 7a of the hollow spindle. At the lower end of the hollow spindle there is provided a twist limiter 11 around which or through which the yarn components E, D, and G 1 or G2 to be twisted together are guided. Twist limiters of this type are also referred to as limit regulators. A twist limiter of this type is disclosed for example in German Offenlegungsschrift 2,053,385.

The axis of the hollow spindle 7 is advantageously located in the thread running plane e-e. What is meant by the thread running plane in this case is that plane which passes through the line of contact L between delivery roller 2a and press roller 2b, and also through the yarn components E and G1 and G2 which are combined and false-twisted downstream of the line of contact L.

In the thread running direction, a pair of drawoff rolls 1 2 is located downstream of the twist limiter 11. After this pair of draw-off rolls, the finished fancy yarn is wound up in a known manner (not shown). The speed ratio of the pair of draw-off rolls to the pairs of delivery rollers 2 and 6 is also infinitely variable.

As can now be seen particularly from Figs. 3 and 4, a fixed thread guide 13 for the ground thread G1 is provided on at least one end of the press roller 2b in the vicinity of the line of contact L. The said fixed thread guide 13 is also substantially located in the thread running plane e-e. A second similarly designed thread guide is also located advantageously on the other end of the press roller 2b for the ground thread G2.

Since the two thread guides are similarly designed, only one of them is described in detail below. The thread guide 13 is advantageously Ushaped and its two U-shaped legs 13a and 13b extend as far as a holder 14 which is located in the vicinity of the circumference of the press roller 2b. The ends of the two U-shaped legs 1 3a and 1 3b are rigidly connected to the holder 14. The thread guide 13, including its two U-shaped legs 1 3a and 1 3b, is made advantageously of spring steel in order that it may have a certain flexibility.

The holder 14 can be adjusted at right angles to the thread running plane e-e and also in the thread running direction of the false-twisted yarn components E and G 1 or G2.

The axial length of the press roller 2a is advantageously less than its diameter. It is advisable to minimise the axial length of the press roller in order that, on the one hand, a contact between the ground thread G 1 or G2 and the edge of the press roller 2b may be prevented and, on the other hand, the triangular thread formation between the line of contact L, the combination point V of the yarn component and the thread guide 13 may be kept as small as possible.

Fancy yarns are produced by using the apparatus according to the invention in the following manner: For spinning effects one or two ground threads G1 and G2 are drawn in, depending on the desired yarn criteria with regard to strength and appearance. The ground threads G1 and G2 run in this case from bobbins (not shown) to the pair of ground thread delivery rollers 6 via the connecting rod 1 5. Thread running is in this case stabilised by thread guides (not shown). In addition, the ground threads are guided via the helical thread guides 1 6 to the already described thread guides 13 which are located on either side of the press roller 2b.The threading or insertion of the ground threads G 1 and G2 into the thread guides 13 is facilitated because the two U-shaped legs 1 3a and 1 3b extend as far as the circumference of the press roller 2b and in this case run parallel to one another over at least part of their overall length.

The fancy yarn component E, which can consist of one roving or a plurality of rovings, runs into the drawing mechanism 4, 5. A preliminary draft takes place between the back roll 5 and the centre roll 4 and a principal draft takes place between the centre roll 4 and the pair of delivery rollers 2. The fancy yarn component E is clamped at the line of contact between the delivery roller 2a and the press roller 2b. After the line of contact L, the two ground threads G1 and G2 run together with the fancy yarn component at the combination point V.They are false-twisted between the said combination point V and the twist limiter 11. Since the fancy yarn component V is fed at a greater delivery speed than the two ground threads G 1 and G2, the fancy yarn component is wound around the ground threads and the desired effects are produced depending on delivery speed and tension, and on the rotational speed of the hollow spindle 7. In addition, the binding thread B together with the false-twisted yarn components E, G1 and G2, is guided through the hollow spindle 7 substantially parallel to the false-twisted yarn components. As a result of the rotation of the hollow spindle, the ground threads G 1 and G2 and the fancy yarn component E are twisted with the binding thread in the thread running direction below the twist limiter 1 whereby the effects are established and cannot be altered. The fancy yarn formed between the twist limiter 11 and the draw-off rolls 12 is then wound in the known manner.

By adjusting the thread guide 13 in the thread running direction of the false-twisted yarn components G 1, G2 and E, the combination of the individual components can be adapted to the twisting conditions in each case which occur as a result of different rotational speed, delivery speed and thread tension. By adjusting the thread guides 1 3 in the direction of the centre roll 4, the combination point V is moved nearer to the line of contact L and vice versa.

If the fancy yarn is made of only one ground thread G 1 and one fancy yarn component, the ground thread runs with less lateral deflection than the fancy yarn component since the latter has a lower thread tension. Coming from the line of contact, the fancy yarn component, having been strongly deflected, is wound onto the ground thread G 1. A more or less roughened fancy yarn is formed, depending on whether the ground thread is inserted at the right-hand or lefthand thread guide 13, when the hollow spindle 7 rotates in the same direction. This is due to a more or less strong friction between the laterally deflected fancy yarn component and the press roller 2b. In the case of the apparatus according to the invention, this influence on the fancy yarn component can be deliberately employed to create different effects.

Without using the drawing mechanism, twisting effects are produced merely by using the pairs of delivery rollers 2 and 6 and by different delivery speeds for ground threads G 1, G2 and fancy yarn E. Different effects can also be achieved in this case by adjusting the thread guide 1 3 and therefore by varying the position of the combination point V.

Claims

1. Apparatus for producing fancy yarn, comprising at least one pair of delivery rollers for feeding an effect-forming yarn component, which pair of rollers consists of a driven delivery roller and a press roller pressed against said roller, a device for feeding a ground thread, a hollow spindle which carries a binding thread bobbin and comprises a twist limiter, and a pair of draw-off rolls, characterised in that, at least at one end of the press roller (2b) in the vicinity of the line of contact (L) of the delivery roller (2a) and press roller (2b), a fixed thread guide (13) for the ground thread (G 1, G2) is arranged substantially in the thread running plane (e-e) passing through the line of contact (L) and through the yarn components (E, G 1, G2) which are combined and false-twisted after the line of contact (L).

2. Apparatus according to Claim 1, characterised in that a thread guide (13) is arranged at each end of the press roller (2b).

3. Apparatus according to Claim 2, characterised in that the axial length of the press roller (2b) is less than its diameter.

4. Apparatus according to Claim 1 or 2, characterised in that the thread guide (13) can be adjusted in the thread running direction of the false-twisted yarn components (E, G 1, G2).

5. Apparatus according to Claim 1 or 2, characterised in that the thread guide (13) can be adjusted at right angles to the thread running plane (e-e).

6. Apparatus according to any one of the Claims 1-5, characterised in that the thread guide (13) is U-shaped and its two U-shaped legs (1 3a, 1 3b) extend as far as a holder (14) which is located in the vicinity of the circumference of the press roller (2b), at least one of the U-shaped legs (1 3a, 1 3b) being connected to the said holder (14).

7. Apparatus according to Claim 6, characterised in that the two U-shaped legs (1 3a, 1 3b) run parallel to one another at least over part of their overall length.

8. Apparatus according to Claim 6 or 7, characterised in that the thread guide (13, 13a, 1 3b) is made of spring steel wire.

9. Apparatus according to any one of the Claims 1-8, characterised in that the axis of the hollow spindle (7) is located in the thread running plane (e-e) and the line of contact (L) between the pair of delivery rollers (2a, 2b) is perpendicular to the axis of the hollow spindle.

10. Apparatus according to any one of the Claims 1-9, characterised in that there is provided for the ground thread or ground threads (G 1, G2) a separate pair of delivery rollers (6), the delivery speed of which is infinitely variable.