EP1847639B1 - Yarn severing sinker of a flat bed knitting machine - Google Patents

Description

The invention relates to a thread cutting board of a cutting device of a flat knitting machine with a thread catching element and a drive element, a cutting device of a flat knitting machine and a flat knitting machine.

So that a finished piece of knitted fabric can be automatically removed from the knitting machine, all threads must be separated from the knitted piece. For this purpose, the threads are preferably clamped between the thread guide and a separation point (see, eg EP 0 990 724 A ).

For this purpose, devices are known which can be mounted on both sides of a needle bed. They consist of a cutting bed, in which a plurality of equally spaced grooves are introduced. In these grooves, one-piece thread cutting boards are arranged, which are displaceable in the same directions as the knitting needles. The movement of the thread cutting boards is initiated via the same knitting lock, which also controls the knitting needles. The thread cutting boards thus carry out the same movements as the knitting needles. Thus, the position of the thread insert is the same.

If the design of the catch hook of the thread cutting board is so high that the thread is reliably detected when the thread guide has only a short overflow path over the thread cutting board, collisions can occur with the thread guide. If the thread cutting boards are arranged relatively close to one another, collisions with a parked thread guide can occur when the thread cutting board executes its advancing movement for detecting the thread.

Object of the present invention is to provide a thread cutting board, with which the above-mentioned disadvantages can be avoided.

According to the invention this object is achieved in a particularly simple and surprising manner in that in a thread cutting board of the type mentioned, the thread catching element and the drive element are movable relative to each other at least within limits. Characterized in that the thread cutting board in comparison to the prior art now consists of several parts, in particular two parts, the front part of the thread cutting board, namely the thread catching element, perform a deviating from the purely linear movement of the drive element movement and thus moved out of the range of a yarn guide become. As a result, collisions can be reliably prevented. The introduction of movement into the thread cutting board via a foot that can be attached either to the drive element or another element.

In a particularly preferred embodiment it can be provided that the thread catching element is pivotable relative to the drive element. As a result, it can be pivoted out of the area of the thread guide.

It is particularly advantageous if the thread catching element and the drive element are coupled to one another via a coupling with play. By this measure, it is possible that the thread catcher element is retracted with a delay from its position of maximum deflection. Thus, can to be maintained with the retraction until the thread guide is at a safe distance from the thread catching element.

In this context, it is particularly preferred if propulsion means for propelling the thread catching element and different retraction means are provided in a coupling area. Due to the different propulsion means and retraction means, the time delay can be realized. For example, the thread catching element and the drive element can be in direct contact with each other during the propulsion. On the other hand, they can have a certain distance from each other during a return movement.

In principle, a wide variety of couplings are conceivable, for example a tab coupling or the like with a time delay element. However, a playful coupling can be implemented particularly simply if the coupling has a rear grip for a head piece (for example, a thickening) of a coupling portion of one of the elements, in particular of the thread catching element.

In a preferred embodiment, the drive element may have a slot for receiving the head piece of the coupling portion. Furthermore, the coupling portion may have a shaft which passes through a slot opening into the slot. The boundaries of the slot can limit the vertical displacement of the coupling portion and thus the thread catching element. In addition, the boundaries of the slot may define a pivot axis. Due to the interaction of the elongated hole with the head piece, a relative movement in the direction of displacement of the drive element is possible. At the same time, however, a pivoting movement is made possible. The coupling section can also be located in the drive element, and the slot for receiving the head piece of the coupling region in the thread catching element.

In a preferred embodiment of the invention can be provided that the thread catching element has a control cam or a control for cooperation with a control or a control cam of a cutting device. This can ensure that the thread catching element performs a predetermined, defined movement.

In a preferred development it can be provided that the control cam has at least two control levels or control sections. In this case preferably causes a control level or the control section, a movement of the thread catching element in the same plane as the drive element and the other control level or the control section, the pivotal movement of the thread catching element.

The control cam may be formed as a control groove or control contour, wherein the control groove is preferably formed in the thread catching element and the control contour is preferably formed on one side of the thread catching element. In embodiments, two control contours - one at the top and one at the bottom - can be provided on the thread catching element.

Furthermore, it can be provided that the drive element comprises a guide, in particular a guide groove. This can ensure that the drive element performs a purely linear movement. Preferably, the guide of the drive element is straight and slides the drive element along a sliding plane. Through the guide, the drive element receives its height fixation.

In a particularly preferred embodiment it can be provided that the thread catching element in the region of its free end clamping means, in particular a toothing has. The clamping means can cooperate with a corresponding device of the cutting device and pinch the thread before cutting off the thread. The thread cutting board is thus formed as a clamping cutting board.

The scope of the invention also includes a cutting device of a flat knitting machine with at least one thread cutting board, as described above.

In a preferred embodiment of the cutting device can be provided that the thread cutting board is guided in a groove of a cutting bed, wherein the groove has a lowering groove bottom at one end. The groove base defines a sliding plane for the thread cutting board. The lowering groove base represents a cutout, so that the (pivoting) movement of the thread catching element is not hindered.

Advantageously, the cutting device controls, in particular wires, for cooperation with cams and the leadership of the thread cutting board. Thus, a defined movement of the thread cutting board is ensured. The controls are preferably arranged stationary and round in order to minimize frictional forces.

The scope of the invention also includes a flat knitting machine with a previously described cutting device.

Further features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention with reference to the figures of the drawing, which shows details essential to the invention, and from the claims. The individual features may be implemented individually for themselves or for a plurality of combinations in variants of the invention.

In the schematic drawing embodiments of the invention are shown, which are explained in more detail in the following description.

Fig. 1

eine Draufsicht auf einen Ausschnitt einer Schneideinrichtung;

Fig. 2

eine schematische Draufsicht auf ein Strickschloss, durch welches die Bewegung der Stricknadeln und der Fadenschneidplatinen bewirkt wird;

Fig. 3a - 3e

Seitenansichten einer ersten Ausführungsform einer Fadenschneidplatine bei verschiedenen Schlosspositionen gemäß III-III der Fig. 1;

Fig. 4a - 4e

Seitenansichten einer zweiten Ausführungsform einer Fadenschneidplatine bei verschiedenen Schlosspositionen gemäß IV-IV der Fig. 1.

Show it:

Fig. 1

a plan view of a section of a cutting device;

Fig. 2

a schematic plan view of a knitting cam, by which the movement of the knitting needles and the thread cutting boards is effected;

Fig. 3a - 3e

Side views of a first embodiment of a thread cutting board at different lock positions according to III-III of Fig. 1 ;

Fig. 4a - 4e

Side views of a second embodiment of a thread cutting board at different lock positions according to IV-IV of Fig. 1 ,

The Fig. 1 shows a plan view of a section of a cutting device 10. Several thread cutting boards 1, 100 for clamping and cutting threads are arranged in the longitudinal direction of the cutting bed 5 in each case in a groove 51 side by side. At the end of each groove 51 to the comb gap 40 out there are a clamping device 8 and a blade 9, wherein a thread between a trained as a toothed clamping means at the free end of the thread cutting boards 1, 100 and a clamping device designed as a pinion 8 can be clamped.

Fig. 2 shows a schematic representation of a plan view of a knitting lock 200, by which the movement of the knitting needles and the thread cutting boards 1, 100 is effected.

The lock passage 205 is formed by the knock-out part 201 and the delimiting part 210, which are flanked by the needle knives 220 and 220 '.

A likewise schematically illustrated yarn guide 300 is located in the direction of movement of the knitting cam represented by the arrow X at a distance a behind the center Y of the knitting cam 200.

With the letters A - E, the advancing and retreating positions of the thread cutting board 1, 100 are designated at significant positions, the Fig. 3a to 3e or 4a to 4e correspond.

In position A, the foot 24 of the thread cutting board 1, 100 is located on the ejection part 201. The thread cutting board 1, 100 is in its advancing movement in the direction of the arrow K1, shown in the Fig. 3a and 4a ,

The position B corresponds to the last propulsion position in which the thread cutting board 1, 100 moves as a whole exclusively linear, shown in the Fig. 3b and 4b ,

In position C, the thread cutting board 1, 100 has reached its furthest advancing movement. A thread catching element 3, 103 of the thread cutting board 1, 100 is pivoted to its lowest position, shown in the Fig. 3c and 4c ,

In position D, a drive element 2, 102 of the thread cutting board 1, 100 performs a return movement in the direction of the arrow K2, which acts only delayed on the thread catching element 3, 103, shown in the Fig. 3d and 4d ,

In the position E, the thread catching element 3, 103 and the drive element 2, 102 are again in common return movement, shown in the Fig. 3e and 4e ,

Evidently the Fig. 3a to 3e the thread cutting board 1 is divided into a drive element 2 and a fishing hook having a thread catching element 3, which are successively arranged in the same sliding plane 4 of the cutting bed 5 slidably and coupled together.

The sliding plane 4 represents the straight (horizontal) portion of the groove bottom of the groove 51. The sliding movement of the thread cutting board 1 is introduced via not shown knitting cam parts in the direction of the arrows K1 and K2, which are in communication with the foot 24 of the drive element 2.

The elements 2 and 3 can be moved simultaneously with each other linearly in the direction of comb gap 40, wherein the thread catching element 3 at least with its free end at a certain time in addition to its linear movement can perform a pivoting movement to a position which is lower than the slip plane 4th Das Drive element 2 always performs only a linear movement.

When moving the elements 2 and 3 in the direction away from the comb gap 40, the displacement of the thread catching element 3 takes place with a time delay to the drive element 2.

For coupling the elements 2 and 3, the drive element 2 has at its end facing the thread catching element 3 a slot 22 into which a head piece 32 of a coupling section projects, which is connected via a shaft 31 of the coupling portion with the thread catching element 3.

The end face 25 of the drive element 2 touches the end face 37 of the thread catching element 3 and thereby initiates the advancing movement into the thread catching element 3. The end faces 25, 37 thus form driving means.

The formed as a nose Schlitzberandung 21 of the drive element 2 abuts against the upper side of the shaft 31 and causes its height fixation and thus a limitation for the vertical displacement of the thread catching element. 3

The rear side of the oblong hole 22 is spaced from the head piece 32 when the end face 25 abuts against the end face 37.

In the retraction movement, the boundaries 26 and 27 of the slot 22, which constitute a rear grip for the head piece 32, on the head piece 32. The boundaries 26, 27 therefore form withdrawal means. The head piece 32 simultaneously forms the pivot point for the pivoting movement of the thread catching element 3.

When the movement is initiated via the foot 24 of the drive element 2 in the direction of the arrow K1, the elements 2 and 3 are in direct contact with each other.

When the movement is initiated via the foot 24 of the drive element 2 in the direction of the arrow K2, the element 3 is removed from the element 2 by the specified distance Z. The coupling of the elements 2, 3 thus takes place with game.

The distance Z, the elements 2 and 3 to each other in the movement in the direction of the comb gap 40 away (retraction movement), realizes a time interval by which the movement initiation of the drive element 2 in the thread catching element 3 starts delayed.

The height fixing of the drive element 2 on the sliding plane 4 via a trained as a wire control 6, which is fixed in the cutting bed 5 and protrudes through the guide 23. The length of the guide 23 corresponds to the maximum linear movement that the drive element 2 can perform in the direction of the comb gap 40 and back.

The height fixation of the thread catching element 3 during its linear movement via a designed as a wire control 7, which protrudes through a cam formed as a control cam 33 of the element 3 and is fixed in the cutting bed 5.

The control cam 33 is formed with different height levels 33 ', 33 "If the thread catching element 3 is displaced in the direction of the comb gap 40, it is initially held by the control element 7 at a level corresponding to the drive element 2. Upon further displacement of the element 3 in the direction Comb gap 40 passes the cam 33 with its level 33 ", which is above the level 33 ', the control 7. The thread catching element 3 thus performs a pivoting movement in a position in which the underside of the thread catching element 3 is below the level of the sliding plane 4 ,

evidenced Fig. 3a The drive element 2 and the thread catching element 3 of the thread cutting board 1 are moved together by applying the foot 24 by not shown lock parts in the direction of the arrow K1 from its basic position in the direction of the comb gap 40. The thread catching element 3 is thereby pushed by the drive element 2. The end face 25 of the drive element 2 and the end face 37 of the thread catching element 3 lie flat against each other. The thread catching element 3 is supported in this movement on the level 33 'of the control cam 33 on the control element 7 and is thus kept at the level of the sliding plane 4.

According to Fig. 3b the drive element 2 and the thread catching element 3 of the thread cutting board 1 are further displaced in the direction of the arrow K1 toward the comb gap 40. This is the position in which the end of the pure linear movement of the thread catching element 3 is reached.

The thread catching element 3 is held in this movement further by the control element 7 on the level 33 'of the control cam 33, which corresponds to the level of the sliding plane 4, and is located at the transition to the level 33 "of the cam 33rd

evidenced Fig. 3c the drive element 2 and the thread catching element 3 of the thread cutting board 1 are further displaced in the direction of arrow K1 and are in their furthest advanced position to the comb gap 40 back.

Due to the interaction of the control element 7 with the level 33 "of the control cam 33, the yarn catching element 3 has performed a pivoting movement in the direction of the arrow D for its linear movement in the direction of the comb gap 40 and opposite the drive element 2 has assumed a position in which the underside of the thread catching element 3 below the level of glide level 4 ..

In the presentation of Fig. 3d has been the drive element 2 by applying the foot 24 by unillustrated lock parts in the direction of the arrow K2 from its furthest advanced position in the direction of the comb gap 40 moves away. In the thread catching element 3, no movement has yet been initiated by the drive element 2. It is still in the same position as in Fig. 3c shown.

The head piece 32 is in contact with the boundaries 26 and 27 of the slot 22 of the drive element 2. This results in a distance Z (FIG. Fig. 3e ) between the drive element 2 and the thread catching element 3rd

From the position shown here of the elements 2 and 3 to each other, a movement in the element 3 is initiated by the element 2, which moves in the direction of the arrow K2, whereby the elements 2 and 3 are guided back to their retracted position. The pivot position of the thread catching elements 3 is left by this in the same timing as it was taken during the propulsion.

In the presentation of Fig. 3e has the drive element 2, which moves in the direction of the arrow K2, initiated a movement in the thread catching element 3, whereby the elements 2 and 3 were again guided to its retracted position.

Due to the interaction of the control element 7 with the level 33 'of the control cam 33, the yarn catching element 3 has performed a pivoting movement in the direction of the arrow U for its linear movement in the direction away from the comb gap 40. The thread catching element 3 has thus assumed a position which is equal to the position of the sliding plane 4.

The Fig. 4a to 4e show an alternative embodiment of a thread cutting board 100. Corresponding functional elements are denoted by the same reference numerals as in the Fig. 3a to 3e ,

The structure and the mounting of the drive element 102 and the coupling of the drive element 102 with the thread catching element 103 and the movements of the linear and pivotal movements of the elements 102 and 103 correspond to those of the drive element 2 and the thread catching element 3 of Fig. 3a to 3e ,

The height fixing and movement control of the thread catching element 103 during its linear movement takes place via a control element 108 designed as a wire, which is fastened in the cutting bed 5 and on which the control cam 140 moves along the upper side of the thread catching element 103. The cam 140 is formed as a control contour and has a horizontally extending portion 140 'and an obliquely rising to this extending portion 140 "as control sections.

On its underside, the thread catching element 103 has a control cam 141. This is also formed as a control contour and has a horizontally extending portion 141 'and an obliquely extending to this area 141 "as control sections The area 141 'carries out its sliding movement in the direction of the comb gap 40 and back on the sliding plane 4.

The region 141 "carries out its displacement movement in the direction of the comb gap 40 and back on the inclined plane 4 ', wherein the plane 4' represents a sinking groove bottom If the thread catching element 3 is displaced in the direction of the comb gap 40, then it is deflected by the control element 108 initially held at the level of the drive element 102. As the element 103 moves further in the direction of the comb gap 40, the upper control cam 140 passes the control element 108 with its region 140 ", which lies above the level of the region 140 '.

At this time, reaches the rear end of the portion 141 'of the lower outer contour 141, the edge 4 "of the sliding plane 4. Upon further displacement of the element 103 in the comb gap 40 of the area 141" comes into contact with the inclined sliding plane 4'. The thread catching element 103 thus performs a pivoting movement in a lower position, in which the underside of the thread catching element 103 is below the level of the sliding plane 4.

The situation of Fig. 4a corresponds to that of Fig. 3a , The thread catching element 103 moves with the region 141 'of its underside on the sliding plane 4. The height level is maintained by abutment of the area 140' of the top of the element 103 on the control element 108.

The situation of Fig. 4b corresponds to that of Fig. 3b , The thread catching element 3 is held in this movement further through the region 140 'of the upper side 140, which slides along the control element 108, at the level of the sliding plane 4 and is located at the transition to the area 140 "of the upper cam 140th

The situation in Fig. 4c corresponds to the Fig. 3c , Due to the interaction of the control element 108 with the area 140 "of the upper control cam 140 of the thread catching element 103, this has, in addition to its linear movement in the direction of the comb gap 40, performed a pivotal movement in the direction of the arrow D and assumed a position which is at least in the lower region below the sliding plane 4 lies.

The lower control cam 141 of the element 103 has moved with the region 141 'over the edge 4 "and is now located with its region 141" on the sliding plane 4'.

The Fig. 4d corresponds to Fig. 3d , The introduction of movement into the drive element 102 results in a distance Z ( Fig. 4e ) between the drive element 102 and the thread catching element 103.

From the position shown here of the drive element 102 and the thread catching element 103 to each other by the element 102 which moves in the direction of the arrow K2, a movement in the element 103 is initiated, whereby the elements 102 and 103 are guided back to their retracted position.

The in the Fig. 4e shown situation corresponds to that of Fig. 3e , As a result of the interaction of the edge 4 ", which acts as a control here, with the region 141 'of the lower control cam 141 of the thread catch element 103, this has a pivoting movement in the direction of the arrow U in addition to its linear movement in the direction of the comb gap 40 103 has thus taken a position which is equal to the position of the sliding plane 4.

Claims (16)

1. Thread cutting plate (1, 100) of a cutting means (10) of a flatbed knitting machine, comprising a thread trap element (3, 103) and a drive element (2, 102), characterised in that the thread trap element (3, 103) and the drive element (2, 102) can be moved relative to one another, at least within a limited range.
2. Thread cutting plate according to claim 1, characterised in that the thread trap element (3, 103) is pivotable relative to the drive element (2, 102).
3. Thread cutting plate according to either claim 1 or claim 2, characterised in that the thread trap element (3, 103) and the drive element (2, 102) are coupled to one another with play via a coupling.
4. Thread cutting plate according to any one of the preceding claims, characterised in that advancement means for advancing the thread trap element (3, 103) and separate retraction means are provided in a coupling region.
5. Thread cutting plate according to either claim 3 or claim 4, characterised in that the coupling has a rear engagement for a head piece (32) of a coupling portion of one of the elements (3, 103, 2, 102), in particular of the thread trap element (3, 103).
6. Thread cutting plate according to claim 5, characterised in that the drive element (2, 102) or the thread trap element (3, 103) comprises a slot (22) for receiving the head piece (32) of the coupling portion of the respective other element (3, 103, 2, 102).
7. Thread cutting plate according to claim 6, characterised in that the coupling portion comprises a shaft (31) which passes through a slit which opens into the slot (22).
8. Thread cutting plate according to any one of the preceding claims, characterised in that the thread trap element (3, 103) comprises a control cam (33, 140, 141) or a control element for cooperating with a control element (7, 108) or a control cam of a cutting means (10).
9. Thread cutting plate according to claim 8, characterised in that the control cam (33, 140, 141) comprises at least two control levels (33', 33") or control portions (140', 140", 141', 141").
10. Thread cutting plate according to either claim 8 or claim 9, characterised in that the control cam (33, 140, 141) is formed as a control groove or control contour.
11. Thread cutting plate according to any one of the preceding claims, characterised in the drive element (2, 102) comprises a guide (23), in particular a guide groove.
12. Thread cutting plate according to any one of the preceding claims, characterised in that the thread trap element (3, 103) comprises clamping means, in particular a toothing, in the region of the free end thereof.
13. Cutting means (10) of a flatbed knitting machine comprising at least one thread cutting plate (1, 100) according to any one of the preceding claims.
14. Cutting means according to claim 13, characterised in that the thread cutting plate (1, 100) is guided in a groove (51) of a cutting bed (5), the groove (51) comprising a sinking groove base at one end.
15. Cutting means according to either claim 13 or claim 14, characterised in that the cutting means (10) comprises control elements (6, 7, 108), in particular wires, to cooperate with control cams (33, 140, 141) of the thread cutting plate (1, 100).
16. Flatbed knitting machine comprising a cutting means (10) according to any one of claims 13 to 15.

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