EP1582614B1 - Device for supply of yarn amount - Google Patents

Description

The invention relates to a device for delivering a quantity of thread from a thread bobbin to a thread guide according to the preamble of claim 1.

Among other things, the flat knitting machine has the advantage that, in the case of flat knitted fabrics, the contour and, in the case of three-dimensional knits, the three-dimensional shape can be formed during the knitting process in comparison with the machines which can form textile surfaces. As a result, a knitted piece can be formed with a minimal amount of knitting thread, moreover, no time is needed for cutting work in the further confection.

The development of this knitwear began with the flat knitwear, which is internationally called "fully fashioned". As for a complete piece of knit, z. For example, for a sweater, several "fully fashioned" - knitted parts, namely front, back, sleeves, must be joined together, it is important that all parts can be produced with a uniform contour as possible.

The uniformity of the knitted fabric is achieved so far that the knitting yarn is fed with the most uniform possible tension of the stitch formation. For this purpose, various devices, in particular feeders, have been developed.

In the EP 1 231 310 A1 In addition, a yarn feeding device is described, with which the stitch formation is fed to a defined amount of thread. A conveyor roller pair, which is driven by a controllable electric motor, should deduct from the knitting yarn package, the amount of thread, which is predetermined at the same moment for the stitch formation. Between the conveyor roller pair and the thread guide, the thread is passed through an eyelet. This eyelet is located on a spring-loaded arm, which interacts with a sensor. If the quantity of thread conveyed by the rolls is identical to the amount of thread required for stitch formation, then the arm is in its normal position. If more rolls are fed by the rollers than is needed for the stitch formation, the arm pivots in the direction of its spring force application, and the sensor recognizes the change in angle by how much the yarn feed must be reduced. If less thread is conveyed than is needed for the stitch formation, then the arm is deflected counter to its loading direction by the spring. As a result, the sensor recognizes again from the deflection angle, by how much the thread delivery must be increased.

The amount of thread that can be picked up by the pivoting range of the arm is a quantity of thread reserve that is required when the conveyor system first has to overcome its mass moment of inertia at the start before thread feeding begins. The pivotal movement of the arm in the direction of its Federkraftbeaufschlagung is also utilized for yarn retrieval when the yarn guide moves from its position outside the needle chamber to the needle room in the direction of yarn feeding device. Since in this device the thread is withdrawn directly from the bobbin by means of conveyor rollers, it still has the different tensions that have arisen during winding of the bobbin. Since each thread has a greater or lesser elasticity, the different tensions in the thread falsify the amount of thread that is fed into the stitch formation. Therefore, in this system, the arm, with which a thread quantity can be regulated, already necessary from the functional principle. A disadvantage of the device according to the EP 1 231 310 A1 is that a thread amount can be promoted only to the thread guide out and not away from the thread guide. As a result, a thread guide can only be parked far enough from the knitting end that the arm can catch up with the amount of thread when the thread guide moves toward the fabric in the direction of the yarn delivery device. The amount of thread that is then used for stitching is so long no defined amount of thread for this knitting section until the arm is pivoted to its normal position and uses the thread conveyance through the rollers.

From the DE-A-4032402 and the DE-A-3629699 each devices of the type mentioned are known, the DE-A-4032402 a Aufholspanner for storing a quantity of thread and to keep constant the amount of thread in cooperation with a thread brake. The DE-A-3629699 discloses a thread storage and a yarn feed via a friction roller, but which requires a special design of the yarn guide.

The Applicant has set itself the task of providing a device for supplying a yarn amount in a flat knitting machine taking into account each yarn guide movement, so that exactly the amount of yarn mesh formation is supplied, which is actually required and which can be used with standard yarn guides.

This object is achieved by a device having the features of claim 1.

By a yarn guide movement to the device according to the invention to unneeded thread is fed from the means for yarn delivery by a corresponding reversal of direction of the conveying direction again the means for storing a thread amount.

The means for storing a quantity of thread are formed by a feeder on which a withdrawn from the bobbin thread amount wound up and can be delivered by the means for conveying the thread to the thread guide and the thread guide movement to the device to unneeded thread is resumed.

The means for thread delivery comprise a thread eye which is movable in both directions of rotation along the circumference of the feeder. This makes it possible to deliver the exact amount of thread required.

In a further development of the invention, a device for determining the required amount of thread, for example, from pattern, machine and yarn data can be provided, which is coupled to the drive of the means for yarn delivery.

Hereinafter, preferred embodiments of devices according to the invention will be described in more detail with reference to the drawing.

Fig. 1

eine schematische Darstellung einer erfindungsgemäßen Vorrichtung zur Lieferung einer Fadenmenge;

Fig. 2

einen Schnitt längs einer Linie A-A durch die Vorrichtung gemäß Fig. 1;

Fig. 3

eine erste zugeführte Fadenmenge;

Fig. 4

eine zweite zugeführte Fadenmenge.

In detail shows:

Fig. 1

a schematic representation of a device according to the invention for supplying a thread amount;

Fig. 2

a section along a line AA through the device according to Fig. 1 ;

Fig. 3

a first amount of supplied yarn;

Fig. 4

a second amount of yarn supplied.

From the Fig. 1 a device 1 for supplying a quantity of thread is shown, with the help of which during the knitting process in each knitting line each needle is fed exactly the amount of thread that it needs to form a knitted fabric according to the specifications regarding pattern size. The device 1 consists of a feeder 2 as a means for storing a thread amount and a device 3 for promoting the required amount of thread, which are connected to each other via a holder 4 .

The feeder 2 comprises a winding ring 22, which can be driven by a controllable electric motor 21 in the direction of arrow 23 . Characterized a supplied through an eyelet 24 thread 100 is wound on the cylindrical rigidly arranged winding body 25 . The electric motor 21 is driven so that there is always a predetermined number of thread windings 26 on the winding body 25. When applying the thread windings 26 on the winding body 25, the different stresses in the thread can be compensated, which are incurred during winding on a yarn bobbin 10 . A largely uniform tension in the thread 100 ' is the prerequisite that an exact dosage of the amount of thread can be realized.

The device 3 comprises an arm 32 which can be driven by an electric motor 31 so that it circles around the winding body 25 with an eyelet 33 . In this case, the encircling can be carried out counter to the thread winding, so that the thread is unwound from the winding body 25. The encircling can also be performed in the direction of the thread winding, so that the thread is wound onto the winding body 25.

• Fadenmenge für jede Nadel, welche am Strickvorgang beteiligt ist;
• Verteilung der aktiven Nadeln im vorderen und/oder hinteren Nadelbett (Gestrickbreite);
• Geschwindigkeit des Fadenführers;
• Bewegungsrichtung des Fadenführers, von der Spule weg und zur Spule hin;
• Überlaufweg des Fadenführers über die jeweiligen Randnadeln des Gestricks.

The amount of thread for each stitch corresponds to a partial circumference of the bobbin 25. This amount of thread must be unwound by means of the arm 32 in the available time unit of the winding body 25. So that the exact amount of thread exactly the needle concerned can be supplied, the electric motor 31 is controlled via a control signal line 5 by a control unit 6 . A machine control unit 8 supplies via a data line 7 the following information to the control unit 6 for controlling the electric motor 31:

• Amount of thread for each needle involved in the knitting process;
• Distribution of the active needles in the front and / or rear needle bed (knit width);
• Speed of the thread guide;
• Direction of movement of the thread guide, away from the coil and towards the coil;
• Overflow path of the thread guide over the respective edge needles of the knitted fabric.

From these data, the control unit 6 calculates the amount of thread that has to be unwound from the bobbin 25 in a certain time, and controls the electric motor 31 so that the arm 32 with the eyelet 33 in the required speed, a corresponding circular motion about the winding body 25th performs.

The path of the thread 100, 100 ', 100 "of the coil 10 for loop formation 12 is in Fig. 1 exemplified. The thread 100, which is subject to different voltages through the coil winding, is drawn off from the coil 10 via a deflection point U1 . After having passed a thread breakage sensor 15 , it is guided over a deflection point U2 through a hollow axis of the feeder 2 and wound around the winding body 25 with the winding ring 22 and its eyelet 24 . In this case, the stresses in the thread 100 are equalized and the thread 100 'is applied to the winding body 25 with uniform tension. This thread 100 'is unwound as a metered amount of thread 100 "by means of the arm 32 from the winding body 25 and through the hollow shaft of the device 3 via the yarn breakage sensor 15, the Turning points U3 and U4 and fed by means of a yarn guide 11 of the stitch formation 12.

It is shown by way of example that the stitch formation 12 can take place with different needle divisions and mesh sizes. In a section 12 ' medium stitches are formed on a front and a back needle bed. In a section 12 " , stitches of the same size are formed only on the back needle bed In section 12"' , medium stitches are formed only on the front needle bed and in section 12 " , relatively large stitches are formed on the front and back needle bed.

For each individual stitch, no matter in which mesh or in which size it is formed, the device 3 doses the correct amount of thread for the stitch in question.

Fig. 2 shows an enlarged view of the arm 32 and the eyelet 33 of the device 3. If the arm 32 is moved in the direction of arrow 40 , a defined amount of thread from the winding body 25 is unwound. During a movement of the arm 32 in the direction of the arrow 50 , a defined amount of thread is wound onto the winding body 25.

FIGS. 3 and 4 illustrate the supply of different amounts of yarn, as they must be supplied from the device 3 for the same knitted fabric in the same needle space NR , as the yarn guide 11 moves away from the device 1 or to this.

According to Fig. 3 moves the yarn guide 11 in the direction of arrow X of the device 1 away. From the parking position of the yarn guide 11 to a starting needle NA of the needle space NR (distance S1) , no amount of yarn must be unwound from the winding body. From the thread guide position on the needle NA to the thread insertion position for the needle NA (distance S2 ), the amount of thread from the winding body must be unwound, which the Thread guide path S2 corresponds. During the thread insert movement of the thread guide over the entire needle space (route S3 ), a quantity of thread must be unwound from the winding body, which corresponds to the mesh sizes and the needle division of all needles of the needle chamber plus the thread guide path S3. From the thread guide end position to the thread guide parking position (route S4), the amount of thread must be unwound from the winding body, which corresponds to the yarn guide path S4.

Fig. 4 , on the other hand, the movement of the thread guide 11 in the direction of arrow X ' to the device 1 to. From the park position of the thread guide to the starting needle NE of the needle space NR (distance S1' ), the amount of thread must be wound on the winding body, which corresponds to the yarn guide S1 ' , From the thread guide position over the needle NE to the thread insertion position for the needle NE (distance S2 ') , no amount of thread has to be wound on or from the winding body. During the thread insert movement of the thread guide over the entire needle space (distance S3 ' ), a quantity of thread must be unwound from the winding body, which corresponds to the mesh sizes and the needle division of all needles of the needle space minus the thread guide path S3. From the thread guide end position to the yarn guide parking position (route S4 ' ), no amount of thread needs to be wound on or off the winding body.

REFERENCE NUMBERS

1

Device for delivering a quantity of thread

2

fournisseur

3

Device for thread conveyance

4

bracket

5

Control signal line

6

control unit

7

data line

8th

Engine control unit

12

knitting

12 '

section

12 "

section

15

Yarn breakage sensor

21

electric motor

22

wrapping ring

23

arrow

24

eyelet

25

bobbin

26

filament winding

31

electric motor

32

poor

33

eyelet

40

arrow

50

arrow

100

thread

100 '

thread

100 '

thread

U1

deflection

U2

deflection

U3

deflection

U4

deflection

NE

needle

NO

needle chamber

N / A

initial needle

S1

route

S2

route

S3

route

S4

route

S1 '

route

S2 '

route

S3 '

route

S4 '

route

X

arrow

Claims (2)

1. Device (1) for delivering the precisely required amount of thread for each phase of the knitting process to a thread eye (11) of a knitting machine, whereby the device (1) is provided with means for storing an amount of thread and means for thread transport to the thread eye and away from such between a thread spool (10) and the thread eye (11), characterized by, that the means (25) for storage of the amount of thread (100') are formed by a thread regulating wheel (2), onto which an amount of thread (100) that has been pulled off the thread spool (10) can be wound and can be supplied by the means (3) for thread transport to the thread eye (11), and on which by means of the thread eye motion toward the device, unneeded thread (100") can be taken up again, whereby the means (3) for transporting thread comprise a thread eyelet (33) that can be displaced in both directions of rotation (40, 50) in a circular motion around the thread regulating wheel (2), for winding up and winding off a defined amount of thread.
2. Device according to claim 1, characterized by, that a device (6) for determining the amount of thread (100") is provided, which is coupled with the drive (31) of the means (3) for transporting thread.

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