Title of Invention

WARP KNITTING MACHINE , ESPECIALLY CROCHET GALLOON MACHINE

Abstract

In a warp knitting machine with individually driveable guide bars (2) capable of being controlled by means of a control device (36), an especially space-saving and flexible drive is achieved by means of a linear motor (14) . The latter has at least two drive members (28) which are connected in each case to a guide bar (2) and which can be moved back and forth in a common stator (20) by means of a closed magnetic circuit (52). For each drive member (28) there is at least one drive coil (32) which is connected to the control device (36) and the winding plane of which is oriented transversely to the magnetic flux.

Full Text

Warp Knitting Machine, especially Crochet Galloon Machine Technical Field The invention relates to a warp knitting machine, especially a crochet galloon machine, according to the precharacterizing clause of Claim 1. Prior Art Many warp knitting machines of the type mentioned in the introduction are known, first, for example, from WO 92/13127, in which guide bars can be driven individually by means of a pick-off gear, individual displacement elements having different degrees of displacement and being connected by means of coupling members to an actuating device which can be controlled according to the particular pattern. This drive is relatively complicated, and it is necessary to move large masses which make the drive very sluggish and sharply restrict the performance of warp knitting machines. Moreover, due to the number of displacement elements, intermediate elements and members for coupling to a pattern-controlled actuating device, the drive requires a considerable overall volume, this being a great disadvantage, since the guide bars have to be arranged near the knitting point and the space available for drive elements is greatly restricted correspondingly. DE-A-21 19 053 discloses a device for shedding on weaving looms, in which warp yarns are driven by means of a linear motor, drive members being arranged in a common stator, the said drive members in each case moving at least on warp yarn. It cannot be seen how such a linear motor could also be suitable for driving a guide bar of a warp knitting machine. Presentation of the Invention The object of the invention is to improve further a warp knitting machine, especially a crochet galloon machine, of the type mentioned in the introduction. The said object is achieved, according to the invention, by means of the characterizing features of Claim 1. Since an electronically controllable linear motor has at least two drive members which are connected in each case to a guide bar and which are guided back and forth in a common stator by means of a closed magnetic circuit, whilst, moreover, for each drive member there is at least one drive coil which is connected to the control device and the winding plane of which is oriented transversely to the direction of the magnetic flux, a drive which is of extremely small design, yet is effective, is obtained for the guide bars and, moreover, can be controlled in a simple way by means of an electronic control device, so that it is possible for the drive to have a small design unknown hitherto. Correspondingly, the masses and frictional forces are extremely low and electronic control is direct and effective, so that high drive speeds, along with the lowest possible wear, the least generation of noise and minimal energy consumption, are possible. Furthermore, a high degree of control flexibility for patern purposes is achieved. Advantageous refinements of the invention are described in Claims 2 to 1JL. It is possible, in principle, to arrange the drive coil for driving the drive members on parts of the stator and to provide only permanent magnets on the drive members. The refinement according to Claim 2 is more advantageous, however, since it allows a simpler, more efficient and more individual control of the drive members. The drive force can be increased if there is not just one drive coil on the drive member, but two or more drive coils are arranged one behind the other in the direction of movement. A particularly advantageous refinement of the stator is described in Claim 4, the development according to Claim 5 being particularly preferred. The magnets of the stator may be electrical exciting magnets, but, according to Claim 6, they are preferably designed as permanent magnets. A refinement according to Claim 7 is particularly advantageous, since it can then be seen which position the drive member assumes in each case, so that it is not necessary to work with a constant stroke against limit stops, but the control device can also govern the position into which the drive member is to be moved. Particularly as a result of the development of the warp knitting machine according to Claim 8 it is possible to control the drive member exactly in terms of the amount of displacement travel and the stopping position, thereby allowing optimum patterning of the warp fabric to be produced. It is conceivable, in principle, according to Claim 10, for the drive member to execute a curved movement back and forth, but the refinement according to Claim 9 is particularly advantageous. A development according to Claim j^ is advantageous. The cooling device may, for example, be a suction blower which sucks away hot air and therefore also serves, at the same time, for cleaning the linear motor. More intensive cooling is achieved, however, if the cooling device is designed for the supply of cooling air. Brief Description of the Drawings Exemplary embodiments of the invention are described in more detail below with reference to diagrammatic drawings in which: Figure 1 shows the guide bar of a warp knitting machine with a linear motor, in a view of the longitudinal side of the guide bar; Figure 2 shows the linear motor of Figure 1 in the section II-II of Figure 3; Figure 3 shows the linear motor in the section III-III of Figure 2 ; and Figure 4 shows the arrangement of two linear motors. Embodiments of the Invention Figure 1 shows a guide bar 2 of a warp knitting machine in a diagrammatic illustration and to the extent necessary for the present invention, since warp knitting machines and, in particular, crochet galloon machines are known in large numbers. The guide bar 2 is mounted in bearings 4 so as to be displaceable in the longitudinal direction, the bearings themselves being capable where appropriate, depending on the type of design, of executing an up-and-down movement according to the arrow 6, in order to insert a yarn 10 into knitting needles 12 by means of yarn guides 8. A linear motor 14 is connected via a coupling member 16 to the guide bar 2 and imparts a movement 18 back and forth to the latter. The linear motor, illustrated in more detail in Figures 2 and 3, contains a stator 20, on which are arranged a front bearing block 22 and a rear bearing block 24 which guide displaceably back and forth, in bearings 2 6, a drive member 28 which is connected to the guide bar 2 by means of the coupling member 16. The drive member 28 is provided with a widening 30 which extends downwards and in which is arranged a drive coil 32 connected via leads 34 to a control device 36. This widening 30 engages back and forth into a slot 38 of the stator 20 which contains a core 40 made of magnetically conductive material. This core is formed by a base part 42, on which project end parts 44, 46, between which one or more intermediate parts 48, which form the slots 38, are arranged. Fastened to the end parts 44, 4 6 and to the intermediate part 48 are magnets 50 which are preferably permanent magnets and, together with the core, produce a peripherally closed magnetic circuit 52, in which the flux lines running from North to South run, on the one hand, between the magnets and therefore also between the drive coils 32 arranged in the slots and are closed via the end parts and the base part- So as not to disturb this magnetic circuit, the intermediate parts 48 carrying the magnet 50 consist of magnetically non-conductive material. In the present example, the linear motor has an intermediate part 48 which subdivides the region between the end parts 44 and 4 6 into two slots 38, in each of which a drive member 28 is arranged. The arrangement may also readily be such that a larger number of slots and drive members 28 can be arranged. The linear motor, further, is designed in such a way that it co-operates with a sensor 54 for detecting the position of the drive member 28, the said sensor being connected to the control device 36 via a lead 56- For position detection, position markers 58 are arranged on the drive member 28 or on another member, such as, for example, the guide bar, connected to the drive member, so that it is possible, via the control device 36, to establish the position in which the drive member 28 is located. The linear motor, further, is equipped with a cooling device 60 in the form of a blower which blows cooling air over and through the linear motor. Cooling with oil is also possible. The linear motor is driven back and forth and braked by means of a pulsed current of alternating direction, the frequency of the 'pulsed current determining the drive speed. The control device, then, is designed in such a way that, with the aid of appropriate analogue or digital software, it can move the drive member up to a predeterminable position and also hold it in this position. It is consequently possible for the drive member 28 to be pattern- controlled, for example according to the patern to be produced, on the guide bars in terms of different sequences and amounts of movement. The drive may be controlled in various ways known per se. In control by the difference or absolute method, the travel is compared with an absolute reference value- The control always knows the position in which the drive member is located. Even after the warp knitting machine has been switched off and restarted, it can continue to run from the respective position of the drive member. In the incremental method, the increase in travel is used as a measurement quantity and, whenever the warp knitting machine is restarted, the drive member must start from a neutral or basic position determined by a stop. Figure 4 shows that a plurality of linear motors, which in each case drive a plurality, for example 10, guide bars, may be arranged in a warp knitting machine. In the example of Figure 4, a front linear motor 14a is followed by a second linear motor 14b offset to the rear, the linear motors in each case executing the variable stroke H. PATENT CLAIMS 1. Warp knitting machine, especially crochet galloon machine, with individually driveable guide bars (2) capable of being controlled by means of a control device (36) , characterized in that it has an electronically controllable linear motor (14, 14a, 14b) with at least two drive members (28) which are connected in each case to a guide bar (2) and which are guided back and forth in a common stator (20) by means of a closed magnetic circuit (52), whilst, for each drive member (28) , there is at least one drive coil (32) which is connected to the control device (36) and the winding plane of which is oriented transversely to the direction of the magnetic flux. 2. Warp knitting machine according to Claim 1, characterized in that the drive coil (32) is arranged on the drive member (28). 3. Warp knitting machine according to one of Claims 1 or 2, characterized in that for each drive member (28) there are two drive coils (32) arranged one behind the other in the direction of movement. 4. Warp knitting machine according to one of Claims 1 to 3, characterized in that the drive members (28) are arranged in each case in a slot (38) of the stator (20) which has, on both sides of the drive members (28), magnets (50) which 'form a peripherally closed magnetic circuit (32) via a core (40) consisting of magnetically conductive material. 5. Warp knitting machine according to Claim 4, characterized in that the core (40) has a base part (42) and two end parts (44, 46) which project from the latter and which, together with at least one intermediate part (48) projecting from the base part (42) and preferably consisting of magnetically non-conductive material, forms the slots (38) for the drive members (28). 6. Warp knitting machine according to Claim 4 or 5, characterized in that the magnets (50) are permanent magnets. 7. Warp knitting machine according to one of Claims 1 to 6, characterized in that each drive member (28) is assigned a sensor (54) for position detection, the said sensor being connected to the control device (36) . 8. Warp knitting machine according to one of Claims 1 to 7, characterized in that the control device (36) is designed in such a way that each drive member (28) can be controlled individually into any desired Position. 9-• Warp knitting machine according to one of Claims 1 to 8, characterized in that each drive member (28) is guided rectilinearly back and forth. 10. Warp knitting machine according to one of Claims 1 to 8r characterized in that each drive member (28) is guided curvedly back and forth. 11. Warp knitting machine according to one of Claims 1 to characterized in that the linear motor (14, 14a, 14b) is assigned a cooling device (60), Preferably for the supply of cooling medium, such as for example cooling air. 12. Warp knitting machine, especially crochet qallaan machine, substantially as herein described with reference to the accompanyina drawings.

Documents:

1487-mas-1998-abstract.pdf

1487-mas-1998-claims duplicate.pdf

1487-mas-1998-claims original.pdf

1487-mas-1998-correspondence others.pdf

1487-mas-1998-correspondence po.pdf

1487-mas-1998-description complete duplicate.pdf

1487-mas-1998-description complete original.pdf

1487-mas-1998-drawings.pdf

1487-mas-1998-form 1.pdf

1487-mas-1998-form 26.pdf

1487-mas-1998-form 3.pdf

1487-mas-1998-other documents.pdf

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