EP1605085B1 - Thread take-up device - Google Patents

Description

The invention relates to a Fadenaufhol device with a Fadenaufholarm according to the preamble of claim 1.

At the latest with the spread of the "fully fashioned" knitting technique, with which the contour of the knitted piece is formed on the flat knitting machine, Fadenaufholvorrichtungen have become known.

Fully fashioned knit pieces must have exact edges. Therefore, the thread must be securely inserted into each edge needle, regardless of whether the thread guide from the thread strand away or on this moves to the edge needle.

For safe thread insertion into the edge needles, in the thread guide movement towards the thread strand, Fadenaufhol devices have been developed which catch up the amount of thread that corresponds to the distance from the thread guide parking position to the thread insertion position in the edge needle.

All known Fadenaufhol devices have in common that a spring-loaded Aufholarm, which is pivotally mounted on an axle, catching up the thread by pulling the thread away from the thread guide. As a rule, the innermost and outermost pivot position of the pivot arm is mechanically limited.

The advanced thread-retrieving devices monitor the pivoting position of the Aufholarms using sensors. As soon as the Aufholarm in its pivotal movement, in which he recovers the thread reaches the sensor, an electromechanical clamp is closed, thereby interrupting the thread feed from the coil ago. If the Aufholarm reaches the sensor in the movement, which is caused by the yarn supplied to the knitting process, so the electromagnetic clamp opens and the thread feed from the coil forth is free again. Since highly developed flat knitting machines on the left and right machine front each have a Fadenaufhol device and each of these devices can have up to 16 Aufholarme, the great effort is apparent, which is necessary from the number of components (sensors and terminals) and the control technology ago , In particular, the control engineering effort for the assignment of the signals from 32 sensors to the relevant 32 electromagnetic terminals is significant.

From the DE 22 03 376 A a thread tensioner is known, the thread brake actuator has, over which the thread receives the tension that he needs for the knitting process. A Fadenaufholarm and the Fadenbremsteller are mounted on the same axis, One of the yarn brake adjuster is pressed against the other stationary yarn brake actuator via a first spring to obtain an adjustable yarn braking force and the resulting yarn tension. The movable brake disc can additionally be acted upon by a sliding ring by the force of another spring. From the normal working position of the Fadenaufiholarms up to a pivoting angle of 20 °, the sliding ring is held by two plungers at a distance, so that it can not come to rest against a ring on which rests the first spring. At a pivot angle of Fadenaufholarms 2t 24 ° move the plunger in the direction of force of the second spring and the movable brake plate is additionally acted upon by the force of the second spring. As soon as the Fadenaufholarm moves back in the direction of its working position, the sliding ring is opposite to the direction of force of the second spring moves and thereby reduces the loading of the brake actuator by the second spring.

From the CH 620 720 A a thread storage device for a knitting machine is known. The storage device comprises a Fadenaufholarm movable against a spring force, which has two lever arms. At the end of a lever arm, a clamping plate is formed, which cooperates with a movable also against a spring force second clamping plate. The thread is clamped in response to the position of the Fadenaufholarms.

The EP 0 381 908 A1 discloses a device with a Fadenaufholarm having two lever arms. About a lever arm, a bolt against a spring force is displaced. As a result, the contact pressure between two pressure plates, between which a thread is arranged, can be changed.

The invention has for its object to provide a technically simple construction of a Fadenaufhol device, which nevertheless ensures a reliable yarn recovery.

This object is achieved by a Fadenaufhol device with the features of claim 1. The invention is based on the principle of operation of a Fadenaufholvorrichtung in which each Fadenaufholarm a purely mechanically operating thread clamp is assigned, the closing and opening movement is effected by Fadenaufholarm.

If the Fadenaufholarm in its pivoting movement to the thread catching to the limit of a fixed pivoting range, it triggers the closure of the thread clamp. If the Fadenaufholarm comes in its pivoting movement for dispensing thread to this limit of the swivel range, so he opens the thread clamp and locks the open position.

The thread clamp causes its closing movement and its clamping force preferably self-sufficient. The Fadenaufholarm no kinetic energy is needed.

Technical implementations and developments of the above-mentioned principle of operation are described in the claims 2 to 7.

Two preferred embodiments of the invention are shown schematically in the drawing.

Fig. 1

einen Fadenlauf von einer Spule zum Gestrick unter Verwendung einer Fadenaufhol-Vorrichtung;

Fig. 2a - 2c:

eine erste Ausgestaltung eines Hebelarms der Faden- aufhol-Vorrichtung und einer mit diesem zusammen- wirkenden Klemme in verschiedenen Öffnungs- bzw. Schließstellungen;

Fig. 3

eine zweite Ausgestaltung des Hebelarms und der Klemme.

It shows in detail:

Fig. 1

a yarn path from a spool to the fabric using a thread catching device;

2a-2c:

a first embodiment of a lever arm of the yarn catch-up device and a cooperating with this terminal in different open or closed positions;

Fig. 3

a second embodiment of the lever arm and the terminal.

According to Fig. 1 For example, a thread catching device 100 includes a catching arm 1 and a thread clamp 2 . By Aufholarm 1 is a two-armed lever (first lever arm 11 and second lever arm 12 ) is formed, which is pivotally mounted at the pivot point 10 . The first lever arm 11 carries at the lower end of a thread eye 13 and is acted upon in the direction of arrow Z by a spring force. The second lever arm 12 cooperates with a thread clamp 2 and causes or opens the thread clamping.

A thread 40 coming from a spool 30 passes a deflection point 41 and receives its tension on a thread brake 50 , passes through a thread breakage sensor 60 , passes a deflection point 42 , passes through the thread clamp 2, touches a deflection point 43 , passes through the thread eye 13, A deflection point 44 passes and is fed to a knitting process 80 by a yarn guide 70 .

As long as by means of moving in the direction of arrow X yarn guide 70 thread is fed and the yarn guide 70 moves in the same direction of movement from the fabric edge over the distance W in its Abstellposition, the tensile force in the thread 40 is so large that the Aufholarm at its inner boundary 14th is applied.

To form the next row of knitting yarn guide 70 is moved in the direction of arrow Y against the yarn feed. In this case, no thread is consumed over the distance W , therefore, this amount of yarn must be caught up by the Aufholarm 1 (deducted), so that the thread tension does not fall sharply and the thread 40, from an edge needle 90 , can be safely inserted into the needle hook.

This amount of yarn can make up for the Aufholarm 1 that the acted upon by a spring force in the direction Z Aufholarm 1 starting from its inner boundary 14 performs a pivoting movement. The entire pivoting range SG is between the inner boundary 14 and the outer boundary 15. It divides into a region SL in which the yarn path from the bobbin 30 to the yarn guide 70 is not interrupted, and a region SF , in which the yarn 40 above the eye 13 of the Aufholarms 1 is jammed.

When the Aufholarm 1 performs a pivoting movement from its inner boundary 14 to the end of the pivoting range SL, the second lever arm 12 releases the locking of the thread clamp 2, so that this spring-loaded thread clamp 2 jams the thread 40. The Aufholarm 1, if necessary, continue its pivoting movement until it comes to rest on its outer boundary 15.

When the Aufholarm 1 performs a pivoting movement from outside the pivoting range SL toward this, the second lever arm 12 opens the clamp and locks this opening position. When it is pivoted into the area SL, the yarn path from the spool 30 to the yarn guide 70 is no longer interrupted.

From the Fig. 2a it can be seen that the thread clamp 2 is open. This opening position is locked. The Aufholarm 1 is pivoted about an axis 9 so that it rests against its inner boundary 14.

The second lever arm 12 is connected via a hook element 7 with a latch 5 . The hook member 7 comprises with its annular end 71 a bolt 18 which is fixedly connected to the lever arm 12, and with its hook-shaped end 72 a bolt 53 which is fixedly connected to a bolt 5. The bolt 5 is horizontally displaceable in the directions of a double arrow 54 . Due to the shown position of the Aufholarms 1, the latch 5 has been pulled to its extreme left position. In the movement there, he has pivoted another lever 3 about an axis 31 in the position shown. The lever 3 is connected via a hook element 8 with a clamping slide 21 .

The hook element 8 comprises with its annular end 81 a bolt 32 which is fixedly connected to the lever 3, and with its hook-shaped end 82 a bolt 23 which is fixedly connected to the clamping slide 21.

The clamping slide 21 is horizontally displaceable in the directions of a double arrow 26 . In the illustrated position of the Aufholarms 1 and the resulting position of the lever 3, the clamping slide 21 has been pulled to its extreme left position. In this case, a compression spring 24, which is supported on a surface 25 , stretched.

According to Fig. 2a there is a front side with a clamping contour 22 of the clamping slide 21 in the open position to a rigidly arranged clamping piece 4. The passage for the thread 40 is so wide that can be clamped to entangling filaments 40 in all thicknesses.

The pressing force of the spring 24, which causes the closing movement and the clamping force of the clamping slide 21, is greatest in the open position. Thus, the frictional force between a surface 33 of the lever 3 and a surface 52 of the bolt 5 is kept low, the point of articulation of the hook member 8 is close to the plane of a pivot point 31 of the lever. 3

Does the Aufholarm 1 a pivoting movement between its inner boundary 14 to just before the end of the area SL (see Fig. 1 ), it must overcome system inertia its inertia and the friction on the axis 9. The residual force of the spring loading is the thread recovery available.

From the Fig. 2b it can be seen that the thread clamp 2 is open and the lever 3 is almost unlocked.

The Aufholarm 1 is located in the transition region between the pivot areas SL and SF (see Fig.1 ). The second lever arm 12 has come to rest with its nose 17 on the end face 51 of the bolt 5 and moves it in the direction of an arrow 54 '. The force for the pivoting movement of the Aufholarms 1 comes from a spring 61 which exerts a pulling force on an arm 19 in the direction of arrow 62 . The arm 19, like the arm 12, is an arm located above the fulcrum of the recovery arm 1 designed as a two-sided lever.

As soon as the Aufholarm 1, the limit of its pivotal range SL (see Fig.1 ) has reached, the bolt 5 is shifted so far in the direction of arrow 54 'that the lock is released. The prestressed compression spring 24 moves the clamping slide 21 abruptly in the direction of an arrow 26 ', to a Clamping contour 22 abuts against its counterpart 4. With the movement of the clamping slide 21, the lever 3 is pivoted to its vertical position, thereby moving the latch 5 in its outermost position in the direction of the arrow 54 '.

Once the nose 17 rests against the end face 51 of the bolt 5, the Aufholarm 1 must still overcome the mass inertia and friction of the bolt 5 on further pivoting.

When the lock is released, the Aufholarm 1 its pivotal movement in the range SF (see Fig. 1 ) and only has to overcome its inertia and the friction on the axis 9.

From the Fig. 2c it can be seen that the thread clamp 2 is closed. The Aufholarm 1 begins just with the opening movement of the clamping slide 21. The Aufholarm 1 is located in the transition region between the pivot areas SF and SL (see Fig. 1 ).

The positively connected with the lever arm 12 hook element 7 rests with its hook-shaped end 72 on the bolt 53 of the bolt 5 at. The positively connected with the lever 3 hook element 8 abuts with its hook-shaped end 82 on the pin 23 of the clamping slide 21. When pivoting the Aufholarms 1 in the direction of the pivoting range SL (see Fig. 1 ), The latch 5 "is moved. This acted upon its contact surface 52 of the lever surface 33 and pivots the lever 3 about its pivot 31. The pivotal movement of the lever 3 moves the clamping slide 21 in the direction of an arrow 26" in the direction of an arrow 54. The clamping of the thread 40 is released. As soon as the Aufholarm 1 its pivoting range SL (see Fig. 1 ) has reached, the terminal 2 is in full opening and is locked.

During the pivotal movement of the Aufholarms 1 towards its inner boundary 14 (see Fig. 1 ) is the force triggering this movement of Thread 40 applied, which is fed to the knitting process. By this yarn tension, the inertia and friction of the Aufholarm 1 and the terminal 2 must be overcome and also the force of the springs 24 and 61. So that the tension in the thread during the movement of the Aufholarms 1 in the direction described does not rise too much, must in the Material selection and material pairing of the Aufholarms 1 and the terminal 2 to the lowest possible mass and good sliding properties are respected.

A second embodiment of the invention is in the Fig. 3 shown. The position of a Aufholarms 1 ' and a terminal 2' correspond to the representation in Fig. 2a , Depending on the pivot position of Aufholarms 1 ', the terminal 2' is opened by the surface 17 'of the lever arm 12' or triggered their closing movement. The lever arm 12 'assumes with its surface 17', the function of the bolt 5 of Fig. 2a - c ,

Reference numerals:

1

Aufholarm

2

thread clamp

3

lever

4

clamp

5

bars

7

hook element

8th

hook element

9

axis

10

pivot point

11

first lever arm

12

second lever arm

13

eyelet

14

inner boundary

15

outer boundary

18

bolt

19

poor

21

clamping slide

22

clamping contour

23

bolt

24

compression spring

25

area

30

Kitchen sink

31

axis

32

bolt

33

area

40

thread

41

deflection

42

deflection

43

deflection

44

deflection

50

thread brake

51

front

52

area

53

bolt

60

Yarn breakage sensor

61

feather

70

thread guides

71

annular end

72

hook-shaped end

80

knitting process

81

annular end

82

hook-shaped end

90

edge needle

100

Fadenaufhol device

1'

Aufholarm

2 '

thread clamp

12 '

lever arm

17 '

area

Claims (7)

1. Thread pick-up device (100) with a thread pick-up arm (1; 1') and a thread trapper (2; 2') for trapping the thread (40) between a thread spool (30) and a thread eyelet (13) of the thread pick-up arm (1; 1'), whereby the opening and closing of the thread trapper (2; 2') is brought about directly by the movement of the thread pick-up arm (1; 1'), in that the thread pick-up arm (1; 1) is mounted spring-loaded and rotatable and initiates in the one direction of rotation - upon reaching a specified limit of the range of rotation (SL) - the closing of the thread trapper (2, 2'), and in the other direction of rotation - upon reaching the limit - the opening of the thread trapper (2, 2'), whereby the thread pick-up arm (1) comprises a first lever arm (11) with a thread eyelet (13) and a second lever arm (12) working together with the thread trapper (2; 2'), characterized by, that in a rotating motion of the thread pick-up arm (1; 1') toward the limit of the range of rotation (SL), the second lever arm (12) releases a lock of the thread trapper (2; 2'), so that the thread trapper (2; 2') traps the thread (40), and in a rotating motion of the straight grain arm (1; 1') from outside of the range of rotation (SL) towards such, the second lever arm (12) opens the trapping and locks this open position.
2. Thread pick-up device according to claim 1, characterized by, that the trapping force of the thread trapper (2, 2') is independent of the momentum of the thread pick-up arm (1).
3. Thread pick-up device according to one of the preceding claims, characterized by, that the thread trapper (2; 2') comprises a displaceable push-pull device (21) and a trapping piece (4) that is mounted stationary.
4. Thread pick-up device according to claim 3, characterized by, that the push-pull device (21) is retained in the open position against a spring force by a second lever (12; 12') when the thread pick-up arm (1) is not rotated, and is released into the closed position when the thread pick-up arm (1) is rotated beyond a limit of the range of rotation (SL).
5. Thread pick-up device according to claim 3 and 4, characterized by, that the push-pull device (21) is connected with an additional lever (3), that works together with a second lever (12, 12').
6. Thread pick-up device according to claim 5, characterized by, that the second lever (12) is connected with a latch (5), that works together with an additional lever (3).
7. Thread pick-up device according to claim 6, characterized by, that the latch (5) is mounted horizontally displaceable.

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