GB2132646A

GB2132646A - Yarn winding

Info

Publication number: GB2132646A
Application number: GB08334519A
Authority: GB
Inventors: Bojidar Georgiev Totev; Vassil Petrov Petrov; Ilya Tzotchev Ilev; Todor Naydenov Kosturski; Mintcho Bontchev Nedevski
Original assignee: NPK Textilno Maschinostroene
Current assignee: NPK Textilno Maschinostroene
Priority date: 1982-12-29
Filing date: 1983-12-29
Publication date: 1984-07-11
Also published as: DE3347308A1; BG40045A1; GB8334519D0; IT8349588A0

Abstract

Yarn winding apparatus comprises a winding cylinder (4), a bobbin cradle (3) arranged to co-operate with the winding cylinder (4, 5) during winding of the yarn onto a bobbin (1) carried by the cradle (3), yarn traverse means (6), for displacing the yarn axially to and fro along the bobbin (1) during a winding operation, a spool rotatably mounted between the arms of the cradle (3), bearing plates (2) secured one at each end of the spool (13), and each rotatably mounted on a respective one of the cradle arms, a yarn tension monitoring device (7, 8) arranged to monitor the tension in the yarn as it is conveyed to the spool (13), and a braking device operable by the monitoring device in order to control the rotation of the spool, the braking device comprising: an electromagnet fixedly carried by one of the cradle arms, and an armature carried by the corresponding bearing plate, said armature being movable towards the electromagnet in order to exert a braking action on the spool when the electromagnet is energised under the control of the monitoring device (7, 8). <IMAGE>

Description

SPECIFICATION Yarn winding apparatus This invention relates to yarn winding apparatus for use with textile machinery.

An apparatus is known for yarn winding, used for the regulation of the tension in yarns during winding. In this known apparatus, the driving of a winding cylinder of the textile machine is achieved by an electromagnet (built-in), immovably fixed to the winding shaft on which the winding cylinder is mounted. The winding cylinder, made of soft magnetic material, serves to close conductance to the electromagnet. The electromagnet is fed by contact rings and brushes, and a rheostat is included in its circuit. A movable threadguide, representing a two-arm lever with an antiload, through which passes the wound thread, is connected with bearings to the body of the apparatus. A transducer is installed upon the thread-guide, and comprises a rheostat with a glass tube with mercury and a conductor with great resistance, immersed in it.

The disadvantage of this known apparatus are its large overall dimensions, the presence of inertia and instability during the working process, large reactive losses, as well as laying of the yarns one upon the other (also called "picture winding") during their winding.

Another known apparatus has been designed so as to avoid the laying of the yarns one upon the other. This comprises a winding shaft with winding cylinder immovably fixed upon it. A wound bobbin carried by a bobbin arm is pressed against the winding cylinder. Near to the winding cylinder there is an axially movable threadguide, guiding the yarn towards the bobbin. Parallel to the winding cylinder, the apparatus has a separate channel cylinder for the driving of the threadguide.

The channel cylinder is connected through (via) a toothed belt to the shaft of the winding cylinder.

To the guidable part of the toothed belt there is a tensioning roller, and to the guiding part there is situated a periodically functioning pressing roller.

The periodic pressing is achieved by an independent device with a lever system and a transmission reduction gear, driven by an independent electrically operated driver.

The disadvantages of this known apparatus are that it has a complex (sophisticated) kinematics.

Also, it is not possible to regulate the tension of the thread during its winding, by that apparatus.

The present invention has been developed primarily, though not exclusively, with a view to create a simple apparatus for yarn winding, keeping a constant tension of the wound yarn, and simultaneously achieving a traversing movement of the yarn on the bobbin so as to prevent laying of yarns one upon the other with small inertia and overall dimensions of the apparatus, stability during the winding operations and small reactive losses.

According to the invention there is provided yarn winding apparatus comprising a winding cylinder, a bobbin cradle arranged to co-operate with the winding cylinder during winding of the yarn onto a bobbin carried by the cradle, yarn traverse means for displacing the yarn axially to and fro along the bobbin during a winding operation, a spool rotatably mounted between the arms of the cradle, bearing plates secured one at each end of the spool and each rotatably mounted on a respective one of the cardle arms, a yarn tension monitoring device arranged to monitor the tension in the yarn as it is conveyed to the spool, and a braking device operable by the monitoring device in order to control the rotation of the spool, the braking device comprising:: an electromagnet fixedly carried by one of the cradle arms, and an armature carried by the corresponding bearing plate, said armature being movable towards the electromagnet in order to exert a braking action on the spool when the electromagnet is energised under the control of the monitoring device.

The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic illustration of a first embodiment of yarn winding apparatus according to the invention; Figure 2 is a schematic illustration of a second embodiment of yarn winding apparatus; and Figure 3 is a sectional illustration of a braking device for use with winding spools provided in the apparatus of Figure 1 or 2.

Referring now to Figure 1 of the drawings, there is shown yarn winding apparatus comprising a winding cylinder 4, a bobbin cardle 3 arranged to co-operate with the winding cylinder 4 during winding of the yarn onto a bobbin 1 carried by the arms of the cradle, and yarn traverse means for displacing the yarn axially to and fro along the bobbin 1 during a winding operation, such means taking the form of yarn-guiding channels 6 provided in the outer periphery of the winding cylinder 4.

A spool 13 (see Fig. 3) is rotatably mounted between the arms of the cradle 3 by means of bearing plates 2 arranged one at each end of the spool 13 and each rotatably mounted on a respective one of the cradle arms.

A yarn tension monitoring device is arranged to monitor yarn tension as it is conveyed to the spool 1 3 and comprises a jack with a feeler for the yarn.

Thus, the device comprises a yarn guide 7 which is movable according to yarn tension, and a transducer 8 which is responsive to the movements of the guide 7 so as to issue an appropriate signal to a braking device (described in more detail below) which controls the rotation of the spool 1 3 (which is normally driven via the peripheral contact of bobbin 1 with the winding cylinder 4).

During a winding operation, yarn 1 5 is conveyed to the bobbin 1 via the tensionmonitoring guide 7 after the cradle 3 (which is movably connected to the body of the textile machinery in a manner which is not shown in detail) has pressed the bobbin 1 into contact with the winding cylinder 4. Traversing of the yarn on the bobbin is carried out by the channels 6.

An alternative arrangement of yarn traversing is shown in Figure 2, in which there is a plainsurfaced winding cylinder 5 and an axially displaceable yarn guide 1 6 which moves to and fro alongside the winding cylinder 5.

The braking device is operated by the monitoring device 7, 8 in order to control the rotation of the bobbin 1 in dependence upon changes in yarn tension. The braking device comprises an electromagnet 9 which is fixedly carried by one of the cradle arms, and an armature in the form of an anchor 11 which is carried by the corresponding bearing plate 2. The armature is movable towards the electromagnet in order to exert a braking action on the spool 13 when the electromagnet is energised under the control of the monitoring device 7, 8. The armature is axially movably mounted on one or more axial projections 10 on the bearing plate 2, and an intermediate brake disc 12 is arranged between the armature and the electromagnet.The spool 13 is fixed to the bearing plate 2 by means of a fixing element 14 which is fixedly carried by the bearing plate 2 and comprises a pointed pin, a shown.

Alternatively, the fixing element may comprise an elastic friction cam or an elastic O-ring carried fixedly by the bearing plate.

The function of the mechanism is as follows: upon an increase of the tension of the wound thread or yarn, the guide 7 is pivoted. After a given angle of turning, the transducer 8 sends a signal for switching-off the braking device. The speed of winding is therefore increased and the guide 7 then pivots in an opposite direction. At a given angle of turning of the guide 7, the braking device is switched on and the cycle is repeated. Thus there is provided a monitoring system with a reverse connection, by which there is kept a constant tension of the wound thread. As a result of the created braking moment, at every cycle, the bobbin slips upon the winding cylinder 4 or 5. The guiding channels 6 of the channel cylinder 4, or the threadguide 1 6 moving along the smooth winding cylinder 5, replace the wound thread 1 5 in an axial direction. As a result of the slipping of the bobbin relative to the cylinder, the winding is desynchronised and a displacement of the winding is created, and thus there is avoided their laying one upon the other, respectively so-called "picture winding". The intermediate disc 12 is made of softer material than that of the anchor 11 and the electromagnet 9, so that it can be changed, as necessary, when it wears out.

Claims

1. Yarn winding apparatus comprising a winding cylinder, a bobbin cradle arranged to cooperate with the winding cylinder during winding of the yarn onto a bobbin carried by the cradle, yarn traverse means for displacing the yarn axially to and fro along the bobbin during a winding operation, a spool rotatably mounted between the arms of the cradle, bearing plates secured one at each end of the spool and each rotatably mounted on a respective one of the cradle arms, a yarn tension monitoring device arranged to monitor the tension in the yarn as it is conveyed to the spool, and a braking device operable by the monitoring device in order to control the rotation of the spool, the braking device comprising:: an electromagnet fixedly carried by one of the cradle arms, and an armature carried by the corresponding bearing plate, said armature being movable towards the electromagnet in order to exert a braking action on the spool when the electromagnet is energised under the control of the monitoring device.

2. Apparatus according to claim 1, in which the armature comprises an anchor which is axially movably mounted on one or more axial projections on the respective bearing plate.

3. Apparatus according to claim 2, including an intermediate braking disc arranged between the anchor and the electromagnet.

4. Apparatus according to any one of claims 1 to 3, in which the monitoring device comprises a yarn guide movable according to varying yarn tension and a transducer connected to the electromagnet to control energisation or deenergisation of the latter according to the tensioninduced movements of the yarn guide.

5. Apparatus according to any one of claims 1 to 4, in which the yarn traverse means comprises winding channels formed in the winding cylinder.

6. Apparatus according to any one of claims 1 to 4, in which the yarn traverse means comprises a yarn guide which is axially displaceable alongside a plane-surfaced winding cylinder.

7. Apparatus according to any one of claims 1 to 6, in which the spool is fixed to at least the bearing plate provided with the armature by means of a fixing element.

8. Apparatus according to claim 7, in which the fixing element comprises a pointed pin fixedly carried by the bearing plate.

9. Apparatus according to claim 7, in which the fixing element comprises an elastic friction cam fixedly carried by the bearing plate.

10. Apparatus according to claim 7, in which the fixing element comprises an elastic O-ring fixedly carried by the bearing plate.

11. Apparatus according to claim 1 and substantially as hereinbefore described with reference to and as shown in Figures 1 and 3, or Figures 2 and 3 of the accompanying drawings.