EP3034665B1 - Flat knitting machine with stitch pressing means - Google Patents

Description

The invention relates to a flat knitting machine with the features of the preamble of claim 1.

The invention also relates to a method for controlling a flat knitting machine according to the invention.

In order to give products manufactured using knitting technology certain properties with regard to increased or reduced stretchability in the entire knitted fabric or only in partial areas of the knitted fabric, it is known to introduce additional thread material into the knitted fabric in appropriate areas during the production of the actual rows of stitches. These can be weft threads or floating threads, which are introduced into the knitting process using special thread guides, depending on the desired effect, for example. B. rubber threads to increase the elasticity of the knitted fabric or monofilament threads to reduce the stretchability in the horizontal direction can be used. The threads can be inserted over the entire knit width and height or only in certain areas.

Furthermore, the introduction of warp threads into knitted fabrics is known, which extend in the vertical direction through certain areas or the entire knitted fabric and can also change the properties of the knitted fabric.

So-called knitted fabric stripers have also become known for holding down the previous row of stitches when the needle is driven out to form the next row of stitches, but with these it is not possible to hold a weft or floating thread securely in a predetermined position or to move a warp thread to a new position move.

From the DE 10 2013 014 071 A1 a flat knitting machine with a coater is known. The spreader has a finger that extends into the area of a knitting system. This can lead to collisions with elements of the flat knitting machine that move during the knitting process.

The EP 0 310 565 A1 discloses a flat knitting machine in which a box is mounted above a carriage, on the underside of which a base plate is arranged centrally above the needle beds or the comb gap. The plate is also mounted on the box like the slides.

The DE 33 21 227 A1 discloses a flat knitting machine with which stitches that are already on the needle during the knitting process are not pulled up out of the comb gap when this needle is driven out again in the working area of the device. The device for holding down is arranged on a circuit board between the actual carriages.

Hold-down devices are from the EP 0 597 548 A1 and GB 2 068 022 A known.

The object of the present invention is to provide a flat knitting machine which has a device with which different threads can be inserted and/or slipped in and/or a knitted fabric can be held down. In addition, the device should not produce any collisions with moving elements of the flat knitting machine.

This object is achieved according to the invention by a flat knitting machine with the features of patent claim 1. Because the device or the thread contact area is arranged completely outside the knitting system, collisions with elements that are moved during the knitting process cannot occur. If only one knitting system is provided, the device can be arranged at the beginning or end of the knitting system. If several knitting systems are provided on the carriage, the device can be arranged between two adjacent knitting systems as seen in the direction of movement of the carriage. For the purposes of the invention, an arrangement between adjacent knitting systems is also viewed as an arrangement at a beginning or end of one of the knitting systems.

The device is designed in such a way that it is suitable for inserting or stripping weft, warp and/or floating threads into a knitted fabric, and is also suitable for holding down a knitted fabric during stitch formation. This makes it possible to carry out a (weft) thread insertion with all thread guides on all thread guide tracks. The identical device can be used for inserting weft threads, floating threads and warp threads. Furthermore, an incoming thread can be placed securely under the emerging needles and/or sinkers; in particular, a weft thread can be inserted over the entire row of stitches. Furthermore, it is possible to guide warp threads safely to a new position, i.e. to carry out a partial weft thread insertion. 3D knitted fabrics, special stitching and transfer techniques can also be used. All thread guides on the flat knitting machine can be used as weft, warp and/or floating thread guides without any special adjustment. The thread guides of the flat knitting machine are preferably designed as self-sufficiently movable thread guides. This means they can be moved independently of the carriage. One or more thread guides can feed thread over the device in a knitting system.

Thread guides, which are moved by driving devices on the carriage, can also be used.

The flat knitting machine according to the invention has two needle beds, between which a comb gap is formed, the device being switchable between a position close to the comb gap and a position far from the comb gap and/or vice versa. In particular, a thread contact area of the device can be displaced between a position close to the comb gap and a position far from the comb gap. This means that different knitting processes are possible. In particular, it is possible to switch the device even during a carriage movement.

The device can have a thread contact area which, when switching the device from a position far from the comb gap to a position close to the comb gap, first carries out an arcuate movement and then an at least essentially linear movement. The arcuate movement means that the thread contact area can be moved out of the area of the comb gap when the device is moved into an inactive position in such a way that there is no need to fear a collision with thread guides. The linear movement can be a substantially vertical movement, which means that the thread contact area can be positioned exactly above the knitted fabric or the thread to be inserted over the comb gap and the thread contact area can virtually cover the comb gap.

The thread contact area can be arranged at the end of an arm. An adjustment mechanism can be provided through which the thread contact area can be adjusted between a position close to the comb gap and a position far from the comb gap and/or vice versa. The movement of the contact area can be realized by means of a mechanism, for example via a lever mechanism or a four-bar linkage, belt, or even pneumatically. The movement of the contact area can be done inside the knit or outside the knit area. However, the entire width of the fabric does not have to be passed through before the position of the contact area can be changed. The device can be designed in such a way that autonomously driven thread guides can pass by even in an active position of the contact area, ie a position close to the comb gap.

The contact area can be made wider in the longitudinal direction of the needle beds than an arm on which the contact area is arranged. This ensures that threads can be guided over a longer distance.

The contact area can have a groove-like recess directed in the direction of movement of the carriage and/or a groove-like recess aligned obliquely to the direction of movement of the carriage. In particular, the groove-like recess can be designed in the form of a groove. This means that a thread is guided securely and a knitted fabric is reliably held down.

According to a preferred embodiment of the invention, adjustment means can be provided for adjusting the position of the thread contact area near the comb gap. In particular, it can be provided that the thread contact area can be adjusted horizontally, vertically and/or in the longitudinal direction of the needle bed in the position close to the comb gap. This makes it possible to ensure that the thread contact area is optimally positioned in its active position and that no malfunctions occur.

The device preferably has a drive. The device can be switched between a position close to the comb gap and a position far from the comb gap via the drive. Come as a drive For example, stepper, servo or linear motors as well as pneumatic cylinders come into question.

The device is preferably arranged so that it is collision-free with all needle bed elements. The device is completely replaceable and can be retrofitted to existing flat knitting machines. The lowest position of the thread contact area can form the extended position of the mechanism (the dead center).

The scope of the invention also includes a method with the features of patent claim 10. This makes it possible to insert weft, warp and/or floating threads into a knitted fabric and to hold a knitted fabric down during the knitting process.

According to a method variant, it can be provided that a thread guide is moved synchronously with the carriage in an area between two knitting systems of the carriage. This procedure is advantageous for inserting a weft thread over the entire width of the knitted fabric or only in certain knitted areas, as can be the case with intarsia knitted fabrics.

The thread contact area of the device can be brought into a position close to the comb gap before reaching a warp thread selected for displacement and the warp thread can then be taken along by the contact area. This makes inserting warp threads easier. It is also possible to shift several warp threads.

The knitted fabric can be kept low during knitting by the thread contact area. This makes it possible for the knitted fabric to be held securely low in the comb gap when the needles are pushed out. In particular, the following process sequences can be carried out with the flat knitting machine according to the invention:
A weft thread can be inserted by a thread guide selected for inserting a weft thread (whose thread feed part has been brought down from an upper, non-active position away from the comb gap into a thread feed position close to the comb gap) in an area between two knitting systems synchronously with the carriage. A thread contact area of the device, which is located a short distance behind the thread guide in the direction of carriage movement, is brought from an upper non-active position into its lower working position (position close to the comb gap). Due to its geometry, it closes the previously open comb gap and guides the thread of the leading thread guide safely into an area which is located below the driven needles.

In the area of the knitting system associated or assigned to the device, at least one thread guide can follow the device in order to incorporate the thread introduced by the leading weft thread guide into the knitted fabric using a suitable knitting technique. Alternatively, wrapping techniques can also be used.

At the end of the knitted fabric width, the device pivots the thread contact area into the inactive position (position away from the comb gap) and the weft thread guide is parked in its parking position.

If a weft thread is only to be inserted in certain knitted areas, the procedure is essentially the same as described above. The difference is that the weft thread is only inserted into predetermined areas of the knitted fabric and then tied in by appropriately controlling the device and the weft thread guide.

Warp threads running vertically through the knitted fabric can be moved horizontally into a new position precisely within the knitted fabric, individually or in groups, using the device. For this purpose, the thread contact area of the device is brought into its position near the comb gap in the respective carriage direction before reaching the warp thread selected for displacement. The vertical warp thread is caught by the thread contact area and taken along. Once the warp thread has reached its new position, it is tied and secured in its new position using suitable, well-known knitting or transferring techniques. The contact area is then brought back into its position away from the comb gap.

If the device is used as a hold-down device, which can happen both with intarsia knits and with knits over the entire width, the thread contact area of the device is brought into its position near the comb gap during the carriage movement. Unlike weft thread insertion, there is no thread guide in front between the knitting systems. In the position of the thread contact area of the device close to the comb gap, the comb gap is securely closed. The knitted fabric in the comb gap is held securely low as the needles are pushed out. In the area of the knitting system associated with the device, at least one thread guide can follow the device to form stitches. The The thread contact area of the device can be pivoted into its position away from the comb gap both within the knitted fabric and at the end of the knitted fabric width, ie at the end of the knitted fabric. If the at least one thread guide follows the device for stitch formation, the thread guide is parked in its designated parking position.

Further features and advantages of the invention result from the following detailed description of exemplary embodiments of the invention, based on the figures of the drawing, which show details essential to the invention, and from the claims. The features shown there are not necessarily to be understood to scale and are presented in such a way that the special features according to the invention can be made clearly visible. The various features can be implemented individually or in groups in any combination in variants of the invention.

In the schematic drawing, exemplary embodiments of the invention are shown in various stages of use and are explained in more detail in the following description.

Fig. 1

einen Ausschnitt einer Flachstrickmaschine im Bereich des Kammspalts;

Fig. 2

eine vergrößerte Detailansicht der Fig. 1, wobei zusätzlich Platinen eingeblendet sind;

Fig. 3

eine Darstellung einer Vorrichtung zum Einstreifen und Einlegen von Schuss-, Kett- und/oder Flottfäden;

Fig. 4

eine Vorderansicht auf eine Vorrichtung der Flachstrickmaschine.

Show it:

Fig. 1

a section of a flat knitting machine in the area of the comb gap;

Fig. 2

an enlarged detailed view of the Fig. 1 , with additional circuit boards shown;

Fig. 3

a representation of a device for stripping and inserting weft, warp and/or floating threads;

Fig. 4

a front view of a device of the flat knitting machine.

The Fig. 1 shows a representation of a flat knitting machine 100 with a front and a rear needle bed 20, 21, each with needles 30, 31 mounted on them for stitch formation in the direction of the comb gap KS and back. Each needle bed 20, 21 is assigned a carriage 50, 51, which is respectively can be moved along the needle beds 20, 21. Knitting systems with lock plates 40, 41 are arranged on the carriages 50, 51. The lock plates 40, 41 are viewed as part of a knitting system. A knitting system preferably consists of two locks (front - back needle bed). Several knitting systems can be arranged one behind the other on a carriage 50, 51, viewed in the direction of movement of the carriage 50, 51. Lock parts for initiating the movement into the needles 30, 31 are attached to the lock plates 40, 41. A thread guide F is used to feed a yarn G to the needles 30, 31. In the Fig. 1 only one thread guide F is shown. In fact, several thread guides can be provided. The thread guides can be designed as self-sufficiently driven thread guides, which can be moved in particular independently of the carriages 50, 51.

A device 10 for stripping and/or inserting weft, warp and/or floating threads into a knitted fabric or for holding the knitted fabric down during stitch formation is mounted above the needle beds 20, 21 on the front and/or rear carriage 50, 51. The position of the device 10 in the longitudinal direction of the needle bed is at the beginning and/or end of a knitting system or between two knitting systems if several knitting systems are provided. In this case too, the device 10 is located at the beginning of one knitting system and at the end of the other.

The device 10 has a thread contact area 6. This can be moved from an upper non-working position a away from the comb gap via a position b to a lower working position c close to the comb gap. The movement of the thread contact area 6 from position a to position b is arcuate. From position b to position c, the movement is largely linear downwards. In the position c shown, the thread contact area 6 of the device 10 completely covers the comb gap KS. By means of adjustment means not shown here, the position of the thread contact area 6 in position c can be adjusted individually vertically and horizontally. An adjustment in the longitudinal direction of the needle bed is also possible.

To guide the yarn G coming from the thread guide F, the thread contact area 6 in the example shown is groove-like, in particular concave or designed as a groove, both in the longitudinal direction of the needle bed and transversely thereto. However, other yarn-friendly geometries are also conceivable.

The Fig. 2 shows an enlarged section of the Fig. 1 . In addition to the needles 30, 31, boards 60, 61 are shown here. These can also be moved relative to the needle beds 20, 21. From the illustration shown it follows that the thread contact area 6 itself in an active position, ie in position c, i.e. in the position close to the comb gap, does not collide with any movable or non-movable elements of the needle beds 20, 21.

The Fig. 2 It can also be seen that a device 10 can be assigned not only to the carriage 51, but also to the carriage 50. Therefore, a thread contact area 6 'can also be seen.

The Fig. 3 shows schematically the structure of the device 10 for stripping and/or inserting weft, warp and/or floating threads into a knitted fabric or for holding the knitted fabric down during stitch formation. The device 10 has a drive 1. For example, the drive 1 can be designed as a stepper or servo motor or similar. Drive 1 is used to initiate movement. An arm 2 is arranged on the drive axle 1 'of the drive 1 and is connected in an articulated manner to a lever arm 3. At its end facing away from the arm 2, the lever arm 3 is bent and connected to the articulation points 4a - 4d with a four-bar linkage 4. An arm 5 is in turn arranged on the four-bar linkage 4, at the end of which the thread contact area 6 is located. In the example shown, the arm 5 is angled at three points 5a, 5b, 5c. There may also be more or less angled areas. The fact that the arm 5 is designed to be angled several times ensures that the thread contact area 6 and the arm 5 do not collide with movable elements of the flat knitting machine, even in a position of the thread contact area 6 close to the comb gap. The lowest point of the thread contact area 6 is reached when the adjustment mechanism 12 assumes its extended position. The thread contact area 6 is located on a straight end section of the arm 5, which is vertically aligned in the position of the device 10 near the comb gap.

In the Fig. 4 a front view of the device 10 is shown. Furthermore, the thread guide F and a needle bed 21 can be seen. The direction of movement of the carriage 51 is in the direction of arrow R to the left. A number of needles 31 are shown which are in an expulsion movement. The expulsion movement was initiated by a knitting system, not shown. The illustration serves to Illustration of the positions of the thread guide F, the device 10 and the needles 31 in the expulsion movement relative to one another. The distance A of the needles 31 shown to the device 10 is not adjustable during the knitting operation in the said example. However, it can be changed using suitable adjustment means while the flat knitting machine is at a standstill. Motorized adjustment is also conceivable, for example. The distance serves process reliability. On the one hand, it should be kept as small as possible in addition to the following mechanical parts. On the other hand, it must be held in such a way that collisions with circuit boards, for example, can be safely avoided. The illustration shows that the distance A is > 0 mm. This means that the device 10 is at a defined distance from the knitting system, in particular has a distance A from the knitting system. No component of the device 10 extends into the area of the needles 31 and thus into the area of the knitting system. A simple embodiment of a flat knitting machine results when the distance A is constant, i.e. the device 10 is not adjustable.

The distance B of the thread guide F to the device 10 can be adjusted when movement is initiated via the carriage 51, not shown here, by means of driving pins by adjusting the contact areas of the driving pin on the thread guide F. When using a knitting machine with independently driven thread guides, in which the position and travel paths of the thread guides can be freely selected, the distance of the thread guide F from the device 10 can be freely selected and also changed during the stitch formation process.

The Fig. 4 It can also be seen that the thread contact area 6 is wider in the longitudinal direction of the needle beds than the arm 5 of the device 10. In particular, the thread contact area 6 a nose 6a, which is directed towards the knitting system. This extends the guide area for a yarn G. On the other hand, the device 10 can be kept so narrow that no collision with needles and sinkers can occur.

The advantage of the present invention lies in particular in the fact that the device 10 can easily be retrofitted to existing flat knitting machines. There is no need to change the needle beds and no additional moving parts on the needle bed are necessary to hold down a knitted fabric or to be able to insert floating, weft and/or warp threads.

Claims (14)

1. Flat-knitting machine comprising a front and a rear needle bed (20, 21) and a front and a rear carriage (50, 51) which can be moved along the needle beds (20, 21) and on which lock plates (40, 41) of at least one knitting system are arranged, a device (10) being provided for stripping and/or inserting weft, warp, and/or floating threads into a knitted fabric and/or for holding down a knitted fabric during stitch formation, characterized in that a device (10) in each case is associated with the front and rear carriages (50, 51) and is mounted thereon, and a thread contact region (6, 6') of the relevant device (10) is arranged at one end and outside the knitting system of the carriage (50, 51) on which the device is mounted.
2. Flat-knitting machine according to claim 1, characterized in that a plurality of knitting systems per carriage (50, 51) are provided and the devices (10) are arranged between two adjacent knitting systems viewed in the direction of movement of the carriages (50, 51).
3. Flat-knitting machine according to either of the preceding claims,
   characterized in that a comb gap (KS) is formed between the needle beds (20, 21), and the thread contact region (6, 6') of the device (10) can be switched between a position (a) remote from the comb gap and a position (c) close to the comb gap.
4. Flat-knitting machine according to claim 3, characterized in that the thread contact region (6, 6') first performs an arc-shaped movement and subsequently performs a linear movement when the devices (10) are switched from a position remote from the comb gap into a position (a, c) close to the comb gap.
5. Flat-knitting machine according to any of the preceding claims 3 or 4,
   characterized in that an adjusting mechanism is provided, by means of which the thread contact region (6, 6') can be adjusted between a position remote from the comb gap and a position (a, c) close to the comb gap.
6. Flat-knitting machine according to any of the preceding claims 3 to 5, characterized in that setting means for setting the position of the thread contact region (6, 6') close to the comb gap are provided.
7. Flat-knitting machine according to any of the preceding claims,
   characterized in that the thread contact region (6, 6') is designed to be wider than an arm (5) on which the thread contact region (6, 6') is arranged.
8. Flat-knitting machine according to any of the preceding claims,
   characterized in that the thread contact region (6, 6') has a groove-like recess directed in the direction of movement of the carriage (50, 51) and/or a groove-like recess oriented obliquely to the movement direction of the carriage.
9. Flat-knitting machine according to any of the preceding claims,
   characterized in that the devices (10) has a drive (1) for introducing movement for the movement of the thread contact region (6, 6').
10. Method for controlling a flat-knitting machine according to claim 1, wherein the thread contact region (6, 6') is moved along the needle bed (20, 21), before or during a movement of the carriage (50, 51) on which the device (10) is mounted, from a position remote from the comb gap into a position (a, c) close to the comb gap or vice versa.
11. Method according to claim 10, characterized in that a thread guide (F) is moved synchronously with the carriage (50, 51) into a region between two knitting systems of the carriage (50, 51).
12. Method according to any of the preceding claims 10 or 11,
    characterized in that at least one thread guide (F) is moved trailing the device in the knitting direction.
13. Method according to any of the preceding claims 10 to 12,
    characterized in that the thread contact region (6, 6') of the device (10) is brought into a position (c) close to the comb gap before reaching a warp thread selected for displacement, and the warp thread is subsequently entrained by the thread contact region (6, 6').
14. Method according to any of the preceding claims 10 to 13,
    characterized in that the knitted fabric is kept low by the thread contact region (6, 6') during knitting.

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