EP4592437A2

EP4592437A2 - Pattern control arrangement, warp knitting machine herewith and method for adjusting a pattern disc

Info

Publication number: EP4592437A2
Application number: EP25169963.3A
Authority: EP
Inventors: Ronald MASSOTH; Klaus Benno Brandl
Original assignee: Karl Mayer Stoll R&D GmbH
Current assignee: Karl Mayer Stoll R&D GmbH
Priority date: 2025-04-11
Filing date: 2025-04-11
Publication date: 2025-07-30
Also published as: EP4592437A3

Abstract

The present invention relates to a pattern control arrangement (1) for a warp knitting machine. The pattern control arrangement comprises a ring-shaped carrier (2) with a central bore and an outer surface configured for mounting at least one pattern disc, a clamping ring (3) configured to rotationally constrain the carrier (2) to a pattern drive shaft of a warp knitting machine, and at least one first attachment member (8) configured to fasten the clamping ring (3) to the pattern drive shaft of a warp knitting machine. The pattern control arrangement (1) further comprises at least one second attachment member (8) configured to releasably fasten the clamping ring (3) to the carrier (2) and an adjustment mechanism (4) configured to change the relative rotational position of the clamping ring (3) and the carrier (2). Further, the invention relates to a warp knitting machine with such a pattern control arrangement (1) and a method for adjusting a pattern disc.

Description

The present invention relates to a pattern control arrangement for a warp knitting machine, to a warp knitting machine with such an adjustable pattern control arrangement and to a method for adjusting a pattern disc.
During the production of warp knitted fabric in a warp knitting machine, guide needles are moved relative to warp knitting needles or work needles. The guide needles are arranged on a guide bar. Thus, in warp knitting machines, the guide bars must be moved back and forth in a predetermined pattern in order to lay threads around knitting needles in such a way that a knitted fabric is produced. In a warp knitting machine, the torque required for this movement is transmitted from a main drive of the warp knitting machine to a pattern drive and a rotation angle synchronization is carried out between the respective drive trains of the warp knitting machine.
The movement of the guide bars is typically controlled by providing a pattern drive with a pattern control arrangement, e.g. comprising a pattern disc for each guide bar, against which the guide bar normally rests via a tappet. The circumference of the pattern disc is shaped according to a motion curve, which is sensed and transferred to the guide bar by means of the tappet when the pattern wheel shaft rotates. In order to create the necessary connection between the guide bar and the pattern disc, a spring balancer is often used to pull the guide bar back towards the pattern disc during the return movements. Such a pattern control arrangement for a warp knitting machine is generally disclosed e.g. in DE 20 2006 011 577 U1 , EP 3 708 702 A2 or DE 10 2009 042 213 B3 .
Due to the high return forces and in connection with high machine speeds, the pattern shaft bearing is subject to heavy loads. Nevertheless, the pattern discs must be held exactly in their position so that the guide bars are guided accurately enough. Even small deviations can cause the guide needles mounted on a guide bar to collide with knitting needles. In other words, regardless of whether and/or how the drive trains are coupled, the movements of the different active elements must be synchronized within very narrow tolerance ranges in order to prevent component collisions. Especially considering that warp knitting machines are often operated with up to 5000 working cycles per minute, such collisions at high speeds would cause significant economic damage due to reduced productivity of the warp knitting machine and impaired quality of the textile to be produced.
Therefore it is desirable to align the various knitting elements, for example the compound needles and the guide needles, in such a way that their distance from each other at the moment of passing-by each other can be set e.g. with a tolerance of +/-0.05 mm to +/- 0.2 mm from the nominal value of this distance, depending on the application and machine type. Considering for example a warp knitting machine with a nominal pattern disc circumference of approximately 1000 mm, this would require a tolerance of the angular position of approximately +/-0.018° to +/- 0.072° of the nominal position of the pattern.
The pattern control arrangement disclosed in DE 20 2006 011 577 U1 comprises a ring-shaped carrier onto which one or more pattern discs are mounted. The carrier is rotationally constrained to a pattern drive shaft of the warp knitting machine by means of a clamping ring and a screw. If the screw is loosened, the carrier can be rotated in order to adjust its position. However, when the rotationally fixed connection between the shaft and the pattern disc is released, the tension exerted by components of the system, e.g. the spring balancer, may unintentionally rotate the shaft and the pattern disc relative to each other and thus affect the synchronization of the drive train. Such an unintended change may overlap with the intended adjustments and, hence, complicates the adjustment and reduces the achievable adjustment accuracy and/or uses up part of the permissible adjustment tolerance.
It is an objective of the present invention to provide an improved pattern control arrangement and a warp knitting machine with such a pattern control arrangement facilitating adjustment of the pattern control arrangement and increasing its synchronization accuracy.
This objective is essentially solved by a pattern control arrangement as defined in claim 1 and a warp knitting machine as defined in claim 13 and a method as defined in claim 15.
A pattern control arrangement according to the present invention is suitable for use in a warp knitting machine and preferably comprises at least a ring-shaped carrier, a clamping ring and a first attachment member. The carrier may be a substantially sleeve-like component part with a central bore and an outer surface configured for mounting at least one pattern disc. The outer surface may be provided with ribs, grooves or the like profiling for transmitting torque from the carrier to the pattern disc(s). The clamping ring is configured to releasably constrain the carrier at least rotationally to a pattern drive shaft of the warp knitting machine. The carrier and the clamping ring may be arranged concentrically, e.g. abutting each other, on the pattern drive shaft of the warp knitting machine. That is, torque of the pattern drive shaft is transmitted via the clamping ring and the carrier to the pattern disc(s). The clamping ring may be releasably fastened to the pattern drive shaft by means of at least one first attachment member, e.g. a screw. For example, the clamping ring may be a slotted ring with a slot extending parallel to the rotation axis wherein the gap of the slot may be adjusted by means of a screw.
The present invention is based on the idea that the accuracy of the pattern control arrangement may be improved by an adjustment mechanism configured to change the relative rotational position of the clamping ring and the carrier. One or more second attachment member(s) may be provided to releasably fasten the clamping ring to the carrier. In other words, adjusting the synchronization of the shaft and the pattern disc(s) may be effected by loosening the second attachment member(s), then amending the relative orientation of the clamping ring and the carrier by means of the adjustment mechanism and finally re-tightening the second attachment member(s). The present invention reduces the influence of the tension and thus the proportion of unintentional change in the total change and consequently improves the ratio between intentional and unintentional change. Thus, a better setting accuracy is achieved.
The adjustment mechanism of the pattern control arrangement may comprises an eccentric tappet. Rotation of the eccentric tappet may precisely adjust the relative angular orientation of the clamping ring and the carrier. In addition, the eccentric tappet may maintain this orientation until the second attachment member(s) are fully re-tightened. In more detail, the eccentric tappet may for example comprise a pin rotatable in a bore of the clamping ring about a first axis and a tip extending along a second axis which is parallel and offset to the first axis, wherein the tip engages a slotted hole in the carrier. As an alternative to the eccentric tappet, an adjustable gearing may be provided between the clamping ring and the carrier.
According to an aspect of the present invention, the carrier may comprises a substantially sleeve-like main body and at least one disc configured to be constrained to the main body. The disc, when attached to the main body, may form a flange of the carrier protruding substantially radially over the cylindrical outer surface of the main body. The disc may be arranged on a stepped portion or in a recess of the main body on a side facing towards the clamping ring. As an alternative, the disc may be interposed between the main body of the carrier and the clamping ring on the pattern drive shaft of the warp knitting machine.
In an example of the present invention, the slotted hole of the adjustment mechanism is provided in the main body of the carrier. In an alternative example of the present invention, the slotted hole is provided in the disc of the carrier.
According to an independent aspect of the present invention, the pattern control arrangement comprises means for visually determining the relative angular orientation of the clamping ring and the carrier. For example, the orientation may be readable from the position of a reference relative to a scale. This facilitates synchronization in that the adjustment can be directly supervised and verified. Generally, one of the clamping ring and the carrier may comprise an angle scale and the other of the clamping ring and the carrier comprises at least one reference marking arranged such that the angle scale and the reference marking allow determination of the relative rotational position of the clamping ring and the carrier. More specifically, the angle scale may be provided e.g. on the disc of the carrier and the reference marking may be provided on the clamping ring.
The disc may be configured to be releasably fixed on the main body of the carrier in a form-fitting or force-fitting manner. If the scale is provided on the disc, this allows arranging the scale such that reading of the scale is facilitated. Further, the disc may consist of an inner disc part and an outer disc part which may be coupled to each other in a form-fitting or force-fitting manner. If the scale is provided on the outer disc part, the angular orientation of the scale may be adapted to facilitate reading without changing the orientation of the inner disc part.
Further, the first attachment member may comprise at least one screw or threaded bolt guided in a circumferentially extending slotted hole of the clamping ring and configured to be secured in a threaded hole of the carrier. Thus, loosening the first attachment member would permit a limited and guided relative rotation of the clamping ring with respect to the carrier while axially retaining the clamping ring and the carrier.
If the adjustment mechanism, e.g. the pin, protrudes from the clamping ring on the side facing away from the carrier and comprises an interface for a tool, the adjustment mechanism may be operated using a tool. As an alternative, a drive unit and/or actuator may be coupled to the adjustment mechanism such that the actuation of the setting element can also be carried out by a suitable actuator, such as an electric or fluidic rotary drive, including in particular an asynchronous motor, a synchronous motor, a servomotor, a DC motor, a brushless DC motor, a linear drive, an electric cylinder or a piezo actuator. Such a drive unit and/or actuator may be permanently or temporarily connected to the adjustment mechanism and may be controlled via devices of the warp knitting machine. This would allow a fully or partially automatic and/or remote controlled adjustment of the pattern disc orientation.
According to a further aspect of the present invention, a warp knitting machine is provided comprising a drive train with a drive shaft, at least one guide bar carrying guide needles and a pattern control arrangement as described above. At least one pattern disc is rotationally fixed to the carrier of the pattern control arrangement to move the at least one guide bar in a predetermined pattern defined by the pattern disc. Further, the drive train typically comprises at least one pattern drive shaft coupled to the drive shaft wherein the clamping ring of the pattern control arrangement may be releasably constrained to the pattern drive shaft.
According to a still further aspect of the present invention, a method for adjusting a pattern disc of a warp knitting machine is provided, especially by using a pattern control arrangement as described above. The method comprises the provision of at least one pattern disc, a ring-shaped carrier, a clamping ring, at least one first attachment member, at least one second attachment member and an adjustment mechanism. According to the method, the ring-shaped carrier is mounted on a pattern drive shaft of the warp knitting machine, such that the carrier is rotatable relative to the pattern drive shaft. The at least one pattern disc may be provided on the carrier prior to mounting same on the pattern drive shaft or thereafter. Further, the clamping ring is mounted and rotationally constrained on the pattern drive shaft by means of the at least one first attachment member. In this configuration, the relative rotational orientation of the carrier and the clamping ring may be adjusted by means of the adjustment mechanism. Thereafter, the carrier and the clamping ring are rotationally constrained to each other by means of the at least one second attachment member. The latter step is preferably reversable such that releasing the attachment of the carrier and the clamping ring permits repeating the step of adjusting the relative rotational orientation of the carrier and the clamping ring by means of the adjustment mechanism if required.
The above description refers to a pattern control arrangement suitable for driving pattern discs. However, those skilled in the art will understand that the same working principle applies, if drums are used instead of pattern discs, on which pattern chains are guided, for setting these drums.
In the following, non-limiting, examples of the pattern control arrangement and the warp knitting machine are described in more detail by making reference to the drawings, in which:

Figures 1a to 1d: show different views of a pattern control arrangement according to a first embodiment of the present invention;
Figure 2a to 2c: show different views of a pattern control arrangement according to a second embodiment of the present invention;
Figure 3a to 3b: show different views of a pattern control arrangement according to a third embodiment of the present invention; and
Figure 4a to 4b: show different views of a pattern control arrangement according to a fourth embodiment of the present invention.

In the Figures, identical elements and components as well as identical elements and components in different examples or embodiments, i.e. elements and components acting substantially identical or provided for the same purposes but belong to different examples, are provided with the same reference signs.
The pattern control arrangement 1 depicted in Figures 1a to 1c comprises a carrier 2, a clamping ring 3 and an adjustment mechanism 4. In Figure 1a, the carrier 2 and the clamping ring 3 are depicted concentrically in a position as if mounted on a pattern drive shaft (indicated only by its center axis in Figure 1a). The adjustment mechanism 4 extends through the clamping ring 3 and engages the carrier 2. The carrier 2 and the clamping ring 3 are both substantially sleeve-like components each having a central bore 5a, 5b for receiving the pattern drive shaft.
In the embodiment of Figures 1a to 1c, a flange-like disc 6 of the carrier 2 is arranged on a main body 2 of the carrier 2 on the side facing towards the clamping ring 3. A circumferentially extending angle scale 7a is provided on the disc 6 with the scale 7a facing towards the clamping ring 3. Further, one or more reference marking(s) 7b are provided on the outer surface of the clamping ring 3.
The carrier 2 and the clamping ring 3 may be rotationally constrained to each other by means of second attachment members 8, e.g. in the form of screws as depicted. In the depicted example, the clamping ring 3 comprises two circumferentially extending slotted holes into which the two screws are inserted. The carrier comprises two threaded holes for receiving these screws. Loosening the screws permits limited relative rotation between the carrier 2 and the clamping ring 3.
The clamping ring 3 is depicted as a slotted ring with a second attachment member 9, e.g. in the form of a screw, may be used to reduce the gap of the slotted ring, thereby tightening the clamping ring 3 onto the pattern drive shaft.
The carrier 2 further comprises a slotted hole 10 on the side facing towards the clamping ring 3 which is part of the adjustment mechanism 4 as will be described below with reference to Figure 1d.
In the embodiment of Figures 2a to 2c the disc 6 of Figures 1a to 1c is omitted and replaced by a larger disc 11 which is interposed between the carrier 2 and the clamping ring 3 on the pattern drive shaft. Disc 11 is rotationally constrained to the carrier 2 by means of e.g. two screws 12 engaging threaded holes 13 in the carrier. Further, the embodiment of Figures 2a to 2c differs from the embodiment of Figures 1a to 1c in that the slotted hole 10 is provided in the disc 11 which also carries scale 7a.
Figure 1d shows an enlarged detail of Figure 1a specifically depicting the adjustment mechanism 4. The adjustment mechanism 4 comprises an eccentric tappet guided in the clamping ring and in the slotted hole 10. More specifically, the eccentric tappet comprises a pin 14 with an offset tip 15. The pin is rotatable in a bore 16 of the clamping ring 2 about a first axis and the tip 15 extends along a second axis which is parallel and offset to the first axis, wherein the tip 15 engages the slotted hole 10 of the carrier 2. The end of the pin protruding from the clamping ring 3 is provided with an interface for a tool, e.g. a portion having a non-round cross-section.
The embodiment of Figures 3a and 3b differs from the embodiment of Figures 2a to 2c in that the disc 11 is split into an inner disc portion 11a and an outer disc portion 11b which may be coupled to each other in a form-fitting or force-fitting manner. The outer portion 11b carries the scale 7a and the inner portion 11a comprises the slotted hole 10.
While the embodiment of Figures 3a and 3b is depicted with an interface for a tool at the end of the pin 14, the embodiment of Figures 4a and 4b shows an actuator 17 with a motor M attached and coupled to the pin 14. Those skilled in the art will understand that an actuator may be coupled to the pin 14 in the other embodiments in a similar manner.
In the following, the function of the pattern control arrangement 1 will be described in more detail with reference mainly to Figures 1a to 1c. However, the working principle is the same for the other embodiments.
In the state depicted in Figure 1a, the carrier 2 and the clamping ring 3 are clamped on a not shown shaft, after one or more pattern discs (not shown) have been mounted on the carrier 2, using one or more clamping screws 9 so that it is fixed against rotation. In this state, the pattern discs are roughly aligned in their angular position.
Further, screws 8 rotationally connect the clamping ring 3 to the carrier 2. If the screws 8 are released, the clamping ring 3 is no longer rotationally constrained to the carrier 2. In this state, the adjusting mechanism 4 can be actuated by applying a torque to pin 14 guided in bore 16. The rotation of pin 14 and thus the displacement of its eccentric tip 15 which is guided in the slotted hole 10 of the carrier 2 results in changing the angular orientation of the carrier 2 and the clamping ring 3 with respect to each other. Specifically, as the clamping ring 3 is fixed on the shaft, the carrier 2 is rotated relative to the shaft and to the clamping ring 3. The extent of this displacement can be determined by the position of a reference marking 7b with respect to scale 7a. The adjusting mechanism 4 can be used to adjust the synchronization steplessly and very precisely with the aid of the scale 7a. As soon as the required extent of this displacement is reached, a torque-proof connection between the clamping ring 3 and the carrier 2 is re-established by screws 8.
Due to the clamping of the proposed adjusting mechanism 4, only limited displacement caused by the spring tension can occur. However, such a displacement can be reset or readjusted at any time by the proposed adjusting mechanism 4. This prevents operating errors and ensures reproducibility. Reliable functioning of the warp knitting machine is thus ensured.

Reference numerals

1: pattern control arrangement
2: carrier (for pattern disc)
2a: main body of carrier 2
3: clamping ring
4: adjusting mechanism
5a: bore in clamping ring
5b: bore in carrier 2
6: disc of carrier 2
7a: scale
7b: reference marking
8: attachment member
9: attachment member
10: slotted hole
11: disc of carrier 2
11a: inner disc portion
11b: outer disc portion
12: screw
13: threaded hole
14: pin
15: eccentric tip
16: bore
17: actuator

Claims

A pattern control arrangement for a warp knitting machine, the pattern control arrangement comprising:
a ring-shaped carrier (2) with a central bore and an outer surface configured for mounting at least one pattern disc,

a clamping ring (3) configured to rotationally constrain the carrier (2) to a pattern drive shaft of the warp knitting machine, and

at least one first attachment member (9) configured to fasten the clamping ring (3) to the pattern drive shaft of a warp knitting machine,

characterized in that the pattern control arrangement further comprises at least one second attachment member (8) configured to releasably fasten the clamping ring (3) to the carrier (2) and an adjustment mechanism (4) configured to change the relative rotational position of the clamping ring (3) and the carrier (2).
The pattern control arrangement according to claim 1, wherein the adjustment mechanism (4) comprises an eccentric tappet.
The pattern control arrangement according to claim 2, wherein the eccentric tappet comprises a pin (14) rotatable in a bore (16) of the clamping ring (3) about a first axis and a tip (15) extending along a second axis which is parallel and offset to the first axis, wherein the tip (15) engages a slotted hole (10) in the carrier (2).
The pattern control arrangement according to any one of the preceding claims, wherein the carrier (2) comprises a main body (2a) and at least one disc (6, 11) configured to be constrained to the main body (2a).
The pattern control arrangement according to claims 3 and 4, wherein the slotted hole (10) is provided in the main body (2a) of the carrier (2).
The pattern control arrangement according to claims 3 and 4, wherein the slotted hole (10) is provided in the disc (6, 11) of the carrier (2).
The pattern control arrangement according to any one of the preceding claims, wherein one of the clamping ring (3) and the carrier (2) comprises an angle scale (7a) and wherein the other of the clamping ring (3) and the carrier (2) comprises at least one reference marking (7b).
The pattern control arrangement according to any one of claims 4 to 6 and 7, wherein the angle scale (7a) is provided on the disc (6, 11) of the carrier (2) and the reference marking (7b) is provided on the clamping ring (3).
The pattern control arrangement according to any one of claims 4 to 8, wherein the disc (6, 11) is configured to be releasably fixed on the main body (2a) of the carrier (2) in a form-fitting or force-fitting manner.
The pattern control arrangement according to any one of the preceding claims, wherein the first attachment member (9) comprises at least one screw guided in a circumferentially extending slotted hole of the clamping ring (3) and configured to be secured in a threaded hole of the carrier (2).
The pattern control arrangement according to any one of the preceding claims, wherein adjustment mechanism (4) protrudes from the clamping ring (3) on the side facing away from the carrier (2) and comprises an interface for a tool.
The pattern control arrangement according to any one of claims 1 to 10, further comprising a drive unit or actuator (17) coupled to the adjustment mechanism (4).
A warp knitting machine comprising a drive train with a drive shaft, at least one guide bar carrying guide needles and a pattern control arrangement (1) according to any one of the preceding claims,
wherein at least one pattern disc is rotationally fixed to the carrier (2) of the pattern control arrangement (1) to move the at least one guide bar in a predetermined pattern defined by the pattern disc.
The warp knitting machine according to claim 13, wherein the drive train comprises at least one pattern drive shaft coupled to the drive shaft and wherein the clamping ring (3) of the pattern control arrangement (1) is releasably constrained to the pattern drive shaft.
A Method for adjusting a pattern disc of a warp knitting machine comprising the steps of:
mounting a ring-shaped carrier (2) with at least one pattern disc on a pattern drive shaft of the warp knitting machine, such that the carrier (2) is rotatable relative to the pattern drive shaft,

mounting and rotationally constraining a clamping ring (3) on the pattern drive shaft by means of at least one first attachment member (9),

adjusting the relative rotational orientation of the carrier (2) and the clamping ring (3) by means of an adjustment mechanism (4),

rotationally constraining the carrier (2) to the clamping ring (3) by means of at least one second attachment member (8) configured to releasably fasten the clamping ring (3) to the carrier (2).