WO1997049852A1

WO1997049852A1 - Textile machine with a selector for working components

Info

Publication number: WO1997049852A1
Application number: PCT/EP1997/002589
Authority: WO
Inventors: Boris Lukic
Original assignee: Universal Maschinenfabrik Dr. Rudolf Schieber Gmbh & Co. Kg
Priority date: 1996-06-26
Filing date: 1997-05-21
Publication date: 1997-12-31
Also published as: DE19625653A1

Abstract

In a textile machine, especially a knitting machine, with controllable working components (5, 6), at least one machine component (3) supporting the working components (5, 6), at least one working component selector (8) and at least one securing magnet firmly secured to the machine component (3), the particularly reliably selection of the working components (5, 6) is obtained, even for very fine work and high machine speeds with simplified machinery and low construction and control costs, if two securing magnets (1, 2) of different polarity are arranged side-by-side which hold the working components (5, 6) in alternating sequence in their initial positions.

Description

TEXTILE MACHINE WITH A SELECTION FOR WORK ELEMENTS

The invention relates to a textile machine, in particular a knitting machine, with controllable work elements, at least one machine part carrying the work elements, at least one work element selection device and at least one holding magnet rigidly attached to the machine part, which holds the work elements in their starting position.

Textile machines of this type, in particular circular and flat knitting machines, are known for example from the publications DE 15 85 206 A2, DE 20 10 973 A2, DE 21 50 360 AI, DE 25 19 896 AI and DE 36 14 220 A2. Arrangements of this type with controllable working elements and an electromagnetic control system are provided in particular for pattern control and as needle selection devices. The needles are selected by acting directly on the individual knitting elements such as needles, sinkers, springs or the like, or by controlling the ferromagnetic parts of the specified knitting elements, the electromagnetic control system moving transversely to the needle output direction relative to the knitting elements located in the needle channels. So that the working elements reach a starting position required for the selection, permanent magnets are provided which hold the working elements in their starting position for selection against the spring force of trigger springs, possibly after action by lock parts. The permanent magnet arranged in the movable control system therefore slides on the working elements or moves over the working elements. The permanent magnet slides along the working elements until the control system with its selection system reaches the knitting element that is to be selected. This selection area is as wide as the working element and separated from the poles of the permanent magnet by a narrow gap, so that the magnetic field of the permanent magnet can be neutralized in this area by means of a control coil. Under the action of the spring force of a trigger spring, the selected working element is therefore removed from the selection system, while the other working elements are still held in position by the magnetic poles of the permanent magnet.

The magnetic flux in the work elements depends on the number of work elements still adhering or selected to the selection system, so that the electromagnetic attraction force acting on the work elements also changes. The magnetic flux of the control coil with which the permanent magnet is compensated in the selection area must also be changed accordingly. From DE 36 14 220 A2 it is known to provide a Hall probe for measuring the current magnetic flux and to change the current applied to the control coil of the electromagnet as a function of the output signal of the Hall probe.

Another major disadvantage of conventional selection systems of this type is that due to the small area in which the selection is carried out, there is only a short period of time during which the selection area is magnetically neutral. According to one from the

DE-25 56 840 AI known proposal several selection arrangements are staggered next to each other in order to achieve higher working speeds of the textile machine and safer processes for the selection of the working elements. However, this arrangement has the disadvantage that a lot of space is required and, in particular, a large number of permanent magnets and control coils have to be used, which also considerably complicate such machines with regard to manufacture, assembly and maintenance, and give rise to a higher susceptibility ben. A textile machine is known from CH-A-479 738, in which an individual permanent magnet is provided for each needle or selection board, the permanent magnet effect of which is compensated in a controllable manner with a corresponding excitation coil in order to compensate for the

Effect selection of needles. Due to the large number of individual excitation coils and the associated effort for the respective control and wiring of the excitation coils, such a selection device is very complex. The boards, their pretensioning with springs and the components for releasing and locking the boards are also very complicated and expensive. In addition, the excitation of the coils, which are in thermal contact with the needle bed, heats it, which is disadvantageous.

From WO-A-9 202 672 a textile machine is known in which an electromagnetic control system is guided over a needle bed, with stationary intermediate elements made of ferromagnetic material in one in each case in the needle bed for each needle channel or each needle or plate essentially magnetically non-excitable environment are provided in order to conduct a magnetic force flow through these intermediate elements onto the needle or the circuit board. The production of such a control system or of such a needle bed is complex due to the stationary intermediate elements in the needle bed.

From DE 42 25 655, which goes back to the same applicant as the present property right, a knitting machine of the type mentioned is known, in which a holding magnet holding the working elements in their starting position is rigidly attached to the needle bed. The needle selection device has a controllable selection magnet and can be moved without contact over at least one outer surface of the working elements. If a working element is to be selected, the selection magnet becomes excites and generates a magnetic force flow which is opposite to the magnetic force flow of the holding magnet, so that the working element is released from the holding magnet. The working element, for example a circuit board or a needle, has a spring element or a resilient part for the pretension, which moves the working element by its resilient action when the holding force of the holding magnet is released by actuating the selection magnet from the holding magnet so that the feet of the working element can be gripped and controlled by corresponding lock parts. This known arrangement has the disadvantages already described above in connection with other known textile machines that the force for releasing the respective working elements depends on how many working elements are still attached to the holding magnet. If there are little working elements adhering to the holding magnet, this is due to electromagnetic force flow passing through it is large, so that a larger magnetic force flow in the opposite direction has to be applied by the electromagnet in order to select one of the working elements still adhering to the holding magnet. Although the known arrangement has proven itself very well in practice, uncertainties arise in individual cases with regard to a reliable selection of the working elements for the reasons mentioned.

In order to ensure the safest possible, reliable selection of the working elements in the knitting machine known from DE-42 25 655 A1, it is therefore necessary to keep the distance between the permanent magnets and the selection magnet as small as possible. This is also necessary in particular in order to prevent a so-called crosstalk, in which the magnetic field of the selection magnet scatters into the area of neighboring working elements, so that these are released from the holding magnet without being deliberately selected. The likelihood of crosstalk is particularly high if, for example, In the case of knitting machines, the mesh clearance is large, that is, if a relatively large number of working elements are provided in a knitting area. The risk of crosstalk is great, especially in the case of fast-running machines, because the selection magnet is only at the selection point for a very short time, this time either not being sufficient to select the working element at this point or the magnetic force of the selection magnet must be large that it also speaks to neighboring work elements.

The object of the invention is therefore to create a textile machine with a selection system with which, with a simple structure, a reliable selection without the risk. crosstalk is ensured even at high fineness and high working speeds.

Starting from the textile machine mentioned at the outset, this object is achieved according to the invention in that two holding magnets with different polarity are arranged next to one another, which hold the working elements in their respective starting positions in alternating order.

Because of the feature according to the invention of providing two holding magnets with different polarity, it is possible to hold only every second working element on a holding magnet in their starting positions, so that the distance between the working elements to be released by a holding magnet is doubled compared to conventional devices . In this way, the risk of crosstalk is significantly reduced and the narrow tolerance requirements to be observed in conventional machines with regard to the magnetic flux of the selection magnet or the distance between selection magnets on the one hand and holding magnets or working elements on the other hand are eliminated by the measures according to the invention - lig. This makes the selection considerably safer and the designer is given greater freedom in designing the selection system, which is a great advantage particularly in the case of textile machines, for example knitting machines with high finenesses and / or high working speeds.

The use of two holding magnets with different polarities for adjacent work elements also has the property which is particularly advantageous for selection security that when a work element is selected, the adjacent work element adheres to the other holding magnet all the more reliably and reliably because the force flow of the selection magnet when selecting a working element increases the force flow or the holding force of the other holding magnet, due to the fact that the polarity of the force flow of the holding magnet with respect to the other holding magnet has the opposite pole direction. The selection device according to the invention thus has the effect that the adjacent work element of a work element to be selected is kept even better in its starting position by the selection of the same.

It is advantageous if adjacent working elements rest on different holding magnets in their respective starting position. This results in the previously explained effect that work elements which are adjacent to a work element to be selected cannot be released, that is to say crosstalk is reliably avoided during the selection process.

According to a particularly advantageous embodiment of the invention, the holding magnets are provided with projections in their support areas for the working elements. In the starting position, the working element therefore only ever rests on the projection of a holding magnet and has to the other holding magnet with opposite polarity a distance because the holding magnets are arranged next to each other and to each other so that the projections of one holding magnet lie between the projections of the other holding magnet. This makes it possible to release the respective working element from the holding magnet by applying a magnetic field opposite the respective holding magnet.

According to one embodiment of the invention, the working element selection device has a controllable selection magnet, which generates a magnetic force flow opposite the respective holding magnet for optional release of the respective needle. It is particularly advantageous if the working element selection device according to an alternative embodiment each has its own controllable selection magnet assigned to the respective holding magnet. In such an embodiment, there is therefore a separate selection magnet for each holding magnet, for example in the form of a controllable one

Electromagnets provided. While a reversal of the polarity of the force flow is required in each case for a device with only one selection magnet for the selection of adjacent working elements, which can possibly lead to delayed selection with regard to the hysteresis curve, it is possible with one selection magnet for each holder magnet to avoid such magnetic reversal of the polarity of the selection magnet, which is particularly advantageous in the case of high precision and high working speeds.

According to a preferred embodiment of the invention, the working element selection device can be moved in a contact-free manner over at least one outer surface of the working elements. The selection magnet or magnets are preferably electromagnets with at least one excitation coil through which a controlled current flows. Preferred each working element is assigned a spring element that presses it into its working position when the working element is selected.

According to a particularly advantageous embodiment of the invention, the holding magnets are arranged between the working elements and the spring elements. In order to avoid repetitions with regard to this embodiment, reference is made to DE-A, which goes back to the same proprietor, with the same registration date. This

To avoid repetition, registration is made the content of the present application.

According to an advantageous embodiment of the arrangement, in which the holding magnets are arranged between the working elements and the spring elements, a magnetic pole of the respective holding magnet faces the working elements and a counter-magnetic pole of the respective holding magnet faces the spring elements. In their starting position, the working elements are preferably in contact with the pole of the respective holding magnet facing them, and in the case of selected working elements, the spring elements associated with these working elements are in contact with the counter-magnetic pole of the respective holding magnet.

According to the last-mentioned embodiments of the invention, the advantages of using two holding magnets with different polarization are combined with the advantages of the embodiment in which the holding magnets are arranged between the working elements and the spring elements. With regard to the details, advantages and refinements of this preferred embodiment of the invention, reference is again made to DE A to avoid repetitions, which in this respect is also made the content of the present documents. The selection method according to the invention can be implemented particularly advantageously in connection with a knitting machine, in particular a flat knitting machine, in which needles or sinkers are provided as controllable working elements and needle beds are used as machine parts carrying working elements. The holding magnets are preferably arranged on the side of the needle bed facing away from the needles or also on the side of the needle bed facing away from the needle bed comb. The holding magnets are preferably attached to the needle bed via a fastening element made of non-magnetic material.

The invention is explained below using preferred exemplary embodiments with reference to the figures. Show it:

Fig. 1 is a schematic representation of an area of

Holding elements under supervision; 2 shows a cross section along the section line II-II drawn in FIG. 1;

3 shows a cross section along the section line III-III shown in FIG. 1; and FIG. 4 shows a schematic representation of an embodiment with separate selection magnets for each holding magnet.

As can be seen from FIGS. 1 to 3, two holding magnets 1, 2 are arranged parallel to one another in the longitudinal direction of a needle bed of a flat knitting machine. The holding magnets 1, 2 have different magnetic polarities. If the polarity of the holding magnet 1 on its upper side represents a south pole S, the holding magnet 2 has a north pole N on its upper side, as indicated in the figures. Of course, the polarity of the holding magnets 1, 2 can also be reversed. The holding magnet 1 has protrusions 4 which project upwards and which are repeated at twice the distance from the arrangement of the working elements or needles or sinkers 5. In a corresponding manner, the holding magnet 2 has projections 7, which are also repeated at twice the distance between the working elements. The projections 4 of the holding magnet 1 are each offset by a needle distance from the projections 6 of the holding magnet 2 in the longitudinal direction of the needle bed 3, so that adjacent needles 5, 6 alternately each on projections 4 of the holding magnet 1 with S polarity and lie on projections 7 of the holding magnet 2 with N polarity when they are in the starting position.

A work element selection device 8 moves over the needles 5, 6 together with a lock slide (not shown), as is shown schematically in FIGS. 2 and 3. This selection device has a controllable electromagnet which can be supplied with current in such a way that it either forms a magnetic south or north pole. When the electromagnet is controlled as the south pole, the magnetic field at the south pole of the holding magnet 1 is weakened or canceled, so that the needles 5 (see FIG. 2) are released from the projection 4 of the holding magnet 1 which represents the south pole and is selected. A spring element, not shown, in this case ensures that the needle 5 is raised upwards and a needle foot, not shown, comes into engagement with lock parts, as is customary.

There is a relatively large distance 9 between the north pole of the holding magnet 2 and the selection device 8 controlled as the south pole, as can be seen in particular from FIG. 2, due to the fact that the needle 5 is on a projection 4 of the holding magnet 1 lies on. Because of this relatively large distance 9 of the North Pole of the holding magnet 2 to the needle selection device 8, the needle 5 is not held in its initial position.

The corresponding process, in which the needle 6 rests on a projection 7 of the holding magnet 2, results when the selection magnet of the working element selection device 8 is excited when it forms a north pole. In this case, the needle 6 lying on the projection 7 is released and selected accordingly.

The embodiment of the invention shown in FIG. 4 differs from the embodiments shown in FIGS. 1 to 3 only in that the working element selection device is in the form of two mutually separate selection magnets 10, 11, each of which contains a holding magnet 1 or 2 are assigned. This embodiment makes it possible to select the needles or sinkers 5 lying on the projections 4 of the holding magnet 1 independently of the needles or sinkers 5 lying on the projections 7 of the holding magnet 2 because the two selection magnets 10 and 11 are separated from one another can be controlled. The advantage of this embodiment is that it is not necessary to reverse the polarity of the selection magnet, as in the exemplary embodiment according to FIGS. 2 and 3, and therefore the control of the selection magnet is simpler and faster switching is possible.

An example of the arrangement and use of selection systems according to the invention is shown and described in the parallel DE-A which has the same filing date. In order to avoid repetition, the content of DE-A is therefore made the subject of the present application.

Due to the alternating north pole and south pole position with the two different magnetically polarized holding raagnete 1,2 it is possible, without impairing the security of selection and without the risk of crosstalk, to increase the distance between the holding magnets 1,2 on the one hand and the working element selection device 8 or 10, 11 or their selection magnet on the other hand hold. As a result, larger tolerances are possible both with regard to the structural dimensions and also with regard to the selection magnet control with correspondingly greater certainties for the selection, the constructional and control-related expenditure also being able to be reduced. The advantage of the present invention is particularly evident in the case of fine divisions up to 20 divisions and at high lock speeds, since adjacent selection points cannot influence one another owing to the features according to the invention, and reliable selection even at lock speeds of 1. 8 m / s and is possible above.

The invention was previously explained on the basis of preferred exemplary embodiments. However, numerous modifications and refinements are possible for the person skilled in the art, without thereby departing from the inventive concept.

Claims

claims

1. Textile machine, in particular knitting machine, with - controllable work elements (5, 6), at least one machine part (3) carrying the work elements (6, 7), at least one work element selection device (8 or 10, 11) and - at least a holding magnet rigidly attached to the machine part (3), which holds the working elements in their starting position, characterized in that two holding magnets (1, 2) with different polarity are arranged next to one another, which hold the working elements (5, 6) in alternating order in their starting positions hold.

2. Textile machine according to claim 1, characterized gekennzeich¬ net that adjacent work elements (5,6) rest in their respective starting positions on different holding magnets (1,2).

3. Textile machine according to claim 1 or 2, characterized ge indicates that the holding magnets (1, 2) in the support areas of the working elements (5, 6) have projections (4 or 7).

4. Textile machine according to one of the preceding Ansprü¬ surface, characterized in that the holding magnets (1,2) are arranged side by side and to each other so that the projections (4 and 7) of the holding magnet (2 and 1) between the projections (7 or 4) of the other holding magnet (2,1).

5. Textile machine according to one of the preceding claims, characterized in that the working element selection device (8 or 10, 11) has at least one controllable have a selection magnet which generates a magnetic force flow opposite the respective holding magnet (1, 2) for optional release of the respective working elements (5, 6).

6. Textile machine according to claim 5, characterized gekennzeich¬ net that the work element selection device (8 or 10, 11) each has its own, the respective Haltemagne¬ ten (1,2) associated selection magnet (10, 11) (Fig. 4).

7. Textile machine according to claim 5 or 6, characterized ge indicates that the at least one selection magnet (8 or 10, 11) is an electromagnet with at least one excitation coil which is flowed through by a controlled current.

8. Textile machine according to one of the preceding claims, characterized in that the work element selection device (8 or 10, 11) can be moved contact-free over at least one outer surface of the work elements (5, 6).

9. Textile machine according to one of the preceding claims, characterized in that each working element

(5,6) is assigned a spring element.

10. Textile machine according to claim 9, characterized gekennzeich¬ net that the holding magnets (1,2) are arranged between the working elements (5,6) and the spring elements.

11. Textile machine according to claim 9 or 10, characterized ge indicates that a magnetic pole of the respective Haltemen¬ gneten (1,2) facing the working elements (5,6) and a counter-magnetic pole of the respective holding magnet facing the spring elements.

12. Textile machine according to one of claims 9-11, characterized in that the working elements (5, 6) in their starting positions on the pole of the respective holding magnet (1, 2) facing them and in the case of selected working elements (5 , 6), the spring elements assigned to these working elements (5, 6) abut the counter-magnetic pole of the respective holding magnet.

13. Textile machine according to one of the preceding claims, characterized in that the textile machine is a

Flat knitting machine with needles (5, 6) as controllable working elements and needle beds (3) as the machine parts carrying the needles.

14. Textile machine according to claim 13, characterized in that the holding magnets (1, 2) are arranged on the side of the needle bed (3) facing away from the needle bed comb.

15. Textile machine according to claim 13 or 14, characterized ge indicates that the holding magnets (1, 2) are fastened to the needle bed via a fastening element consisting of non-magnetic material.