EP1777330A1 - Method for supporting a weft guide element - Google Patents

Abstract

A projectile shuttle (12) containing permanent magnets is moved through the shed over electrically conducting guide bars (16, 17) so that a repelling force is induced that balances gravity. Alternatively the conductors can be placed in the shuttle and the guide bars are magnetic. The magnetic forces are arranged to also provide a centralizing action on the shuttle. The induced current in the guide bars (16, 17) can be augmented by rotating them with a motor (20) and drive disk (19). Independent claims are included for the following: (1) A loom equipped with the required magnetic and electrically conducting elements, with moving guide bars to provide a V-shaped guide configuration (18); (2) A shuttle projecting device for such a loom, using a compressed air cylinder and placed at each end of the shuttle path, with a piston rod preferably lighter than 20 g.

Description

Weaving machines are classified according to the type of weft insertion in certain types.

In the shuttle loom, the weft thread is passed through the shed by means of a weft guide member wound on the weft.

In the loosening looms, projectile weaving machines, rapier weaving machines, air weaving machines and water weaving machines are differentiated. In the two last-mentioned types of machine, the weft thread is conveyed through the shed by means of an air jet or a water jet. These types of weaving machines do not come without supporting elements projecting into the shed. However, these machines have no weft guide elements, which is why with these machines not all types of yarns can be processed. Especially smooth or heavy yarns can not be processed.

The other types of weaving machines operate with weft guide elements, ie with projectiles, grippers or shooters. For the weft insertion support elements for the weft thread guide elements are provided in these looms in the shed protruding. However, these support elements leave traces in the tissue image in fine tissues. Therefore, systems are used for the production of high-quality fabric, in which the weft guide elements on rest on the warp threads of the lower compartment. In the systems with weft guide elements, however, performance is generally impaired by the friction existing between the weft guide elements and the support elements or the warp threads of the lower shed.

The present invention has for its object to provide a powerful method for guiding the weft thread in the shed, with which the above-described friction losses can be at least reduced.

The object is achieved by a method for supporting a weft guide element in the shed of a weaving machine, which is characterized in that the weft guide element is moved relative to a guide channel through the shed, wherein the weft guide element and the electrically conductive guide channel electrically conductive weft guide element and the Guide channel is magnetic and wherein on the weft guide element, a magnetic force is exerted.

Due to the relative movement of the weft guide element and the guide channel, induction currents are generated in the respective electrically conductive component, which in turn cause the formation of a magnetic field. This magnetic field is the same direction to the magnetic field of the magnetic member, so that there is a mutual repulsion of the weft guide member and the guide channel. In either case, when the weft guide member is moved through the shed above the guide channel, a magnetically repulsive force will also deploy an upward force component on the weft guide member. This upward force component supports the weft yarn guide element downwards. When arranging the guide channel above the shed, the resulting repulsive magnetic force can be used to guide the weft thread guide element. Downward components of the weft guide element acting magnetic force and gravity can be at least partially compensated by preferably arranged below the shed permanent magnets. Thus, when using the method according to the invention, the friction between the weft guide element and in the shed from below projecting support elements or the lower warp threads are at least reduced. In principle, two guide channels - one below the shed and one above the shed arranged - are provided.

It is particularly advantageous if the relative movement between the weft guide element and the guide channel and the arrangement of the at least one guide channel is selected such that an upward force component of the magnetic force is generated, which is preferably equal to the force acting on the weft guide element gravity. In this way, the weft guide member floats without contact through the shed by being guided by the guide channel spaced along the guide channel. If the force of gravity is exactly compensated by the magnetic force, the weft guide element retains a constant distance to the guide channel during its entire flight through the shed, irrespective of its length. It can then be made with the inventive method then very wide tissue webs.

By means of a corresponding shaping of the guide channel and / or of the weft thread guide element, the magnetic force acting on the weft thread guide element can also have force components which keep the weft thread guide element centered on the guide channel during its flight through the shed. If the weft thread guiding element is also guided laterally contactlessly by a magnetic force, very uniform fabrics of large width can be produced.

In addition to the weft guide element and the guide channel forming components can be moved. The relative movement between the weft guide element and guide channel is then effected both by the movement of the weft guide element through the shed as well as by the movement of the components of the guide channel. As a result, the courses of the magnetic field lines forming between the weft thread guide element and the guide channel can be influenced by the magnetic field in accordance with the desired guidance of the weft thread guide element.

Further advantages arise when the weft guide element is inserted with a weft thread alternately from both sides in the shed. Although the two-sided weft insertion requires on both sides of the shed corresponding units for the weft insertion as acceleration and braking devices, but these can be weaker and thus more cost-effective because of the alternating load and rest periods designed as the aggregates in one-sided weft insertion, which must withstand a continuous load. Nevertheless, even with a weaker design, in particular the acceleration devices on both sides of the shed overall higher weaving speed can be achieved than in machines with einseitigem weft insertion. Another advantage of the mutual weft insertion is the ability to produce more uniform fabric than machines with one-sided weft insertion, since the ever-present differences in tension of the weft yarns between the entry side and the discharge can be better compensated for two-sided weft insertion than one-sided weft insertion. In addition, with two-sided weft insertion additional colors and / or yarn qualities for the weft insertion can be provided.

The invention also relates to a weaving machine for carrying out a method according to the invention, which is characterized by a formed from at least one electrically conductive or magnetic component Guide channel for at least one magnetic or electrically conductive weft thread guide element.

The guide channel is preferably arranged below the shed. It is also conceivable, however, an arrangement of the guide channel above the shed, wherein the gravity of the weft yarn guide element - if necessary - can be additionally compensated by means of a magnetic force generated below the shed. For this purpose, for example, a second, arranged below the shed guide channel can be provided.

It is advantageous if the guide channel is formed in cross section at least approximately V-shaped. In this embodiment of the guide channel, magnetic force components are created which center the weft guide element during its flight through the shed over the guide channel; so that it is not only supported from below but also guided sideways.

In a preferred embodiment, the guide channel may be formed by at least two rods arranged parallel to one another. The bars form between them a cross-sectionally approximately V-shaped gap, whereby the above-described centering of the weft thread guide element can be achieved.

The rods can also be driven to rotate and / or oscillate and / or pivot. If they are made of an electrically conductive material, for example of aluminum, then the formation of a magnetic field, which interacts with the magnetic field of the magnetic weft thread guiding element, results from the proper movement. The weft thread guide element can be moved by the cooperation of the guide channel to the relative movement between the weft guide element and the guide channel slower through the shed than with a fixed guide channel, ie when the relative movement is generated solely by the movement of the weft thread guide member. The The speed of the self-movement of the guide channel, for example, the rotational speed of the rods, can also be controlled, for example. Depending on the withdrawal force exerted by the weft thread guide element on the weft. In this way, it is possible to keep the flying height of the weft guide element the same as in light yarns by a higher airspeed even with heavy yarns. In the case of very delicate yarns, the flying height of the weft thread guiding element can also be increased at a constant launching speed solely by a greater intrinsic speed of the guide channel.

The guide channel may also be divided to avoid induced by induced eddy currents braking effect on the weft yarn guide member in the longitudinal direction in a plurality of mutually insulated segments.

The loom according to the invention may have on one or both sides of the shed an acceleration device for the at least one weft thread guide element. In principle, all known from projectile weaving acceleration devices can be used.

Furthermore, the weaving machine in a conventional manner one or both sides of the shed a weft yarn selection device and / or a braking device for the at least one weft yarn guide element have. Again, known aggregates can be used.

To further optimize the weaving machine according to the invention in terms of their performance can be used for them an acceleration device having a pneumatic cylinder, the piston rod against one end of the weft guide element is movable and thereby shoots into the shed. This embodiment of the acceleration device has the advantage that it has only a few moving parts. It is understood that this embodiment of the acceleration device not only provides advantages for the weaving machine according to the invention but also for every other kind of projectile weaving machines as well as for shuttle looms.

The invention also relates to a weft yarn guide element for a loom according to the invention, comprising a weft yarn clamping device slidably disposed from one end of the weft yarn guide member to the other end. Due to the displaceability of the clamping device, which can be done, for example, by means of compressed air, the weft waste can be minimized. The weft transfer to the weft guide element can always be done close to the fabric edge. Also, this weft guide element can be used with the same advantages in other weaving machines with positive weft insertion.

Furthermore, the weft thread guide element can be provided with a lower side, which has a cross-sectionally at least approximately V-shaped contour. With this configuration, the lateral guidance of the weft thread guide element can be facilitated via the guide channel.

For the weaving machine according to the invention, at least one weft thread selection device can be used for secure weft yarn transfer to the weft thread guide element having a plurality of thread pliers arranged next to each other on a circular arc with eyelets, which are arranged pivotably together on the circular arc. The thread tongs hold the end of the weft yarns and tension the weft yarns between them and the eyelet, where they can be easily taken over by a clamping device of the weft yarn guide element. The resulting weft waste is minimal. This weft selection device can also be used in rapier weaving machines and also leads there to a drastic reduction of weft waste. Each of the thread tongs can be pivotable with its thread eyelet from a selection position above the weft thread guide element for thread transfer to this down.

Hereinafter, a preferred embodiment of a loom and a method according to the invention will be explained in more detail with reference to the drawing.

Fig. 1

eine perspektivische Ansicht des Führungskanals und der Schussfadeneintragsaggregate einer erfindungsgemäßen Webmaschine;

Fig. 2

eine vergrößerte Detaildarstellung der Webmaschine aus Fig. 1 mit einem Schussfadenführungselement;

Fig. 3

eine Detaildarstellung der Beschleunigungsvorrichtung der Webmaschine aus Fig. 1;

Fig. 4

eine Detaildarstellung der Schussfaden-Auswahlvorrichtung der Webmaschine aus Fig. 1;

Fig. 5

eine Detaildarstellung der Abbremsvorrichtung der Webmaschine aus Fig. 1.

Show it:

Fig. 1

a perspective view of the guide channel and the weft insertion units of a loom according to the invention;

Fig. 2

an enlarged detail of the loom of Figure 1 with a weft thread guide element.

Fig. 3

a detailed view of the accelerator device of the loom of Fig. 1;

Fig. 4

a detailed view of the weft selection device of the loom of Fig. 1;

Fig. 5

a detailed view of the braking device of the weaving machine of FIG. 1.

Fig. 1 shows the weft guide portion of a loom 10 with a guide channel 11 for not shown in Fig. 1, but in particular from Fig. 2 apparent weft guide element 12. The loom 10 is equipped for a two-sided weft insertion and therefore on both sides of the guide channel eleventh with an accelerating device 13, 13 ', a weft selection device 14, 14' and a braking device 15, 15 'equipped. The guide channel 11 is completely below a shed, not shown here. In addition, air-filled pre-chambers 29, 29 'for the acceleration devices 13, 13' can be seen, the function of which will be explained in more detail with reference to FIG.

Fig. 2 shows the embodiment of the guide channel 11 of the machine 10 of FIG. 1 and its function more clearly. The guide channel 11 is formed by two parallel bars 16, 17, which enclose between them a gap V-shaped in cross-section approximately. The rods 16, 17 are driven in the example shown via a disc 19 and an electric motor 20 rotating. Above the guide channel 11, the weft thread guide element 12 is guided without contact. For this purpose, either the rods 16, 17 of an electrically conductive material and the weft guide member 12 made of a magnetic material or vice versa, the rods 16, 17 of a magnetic material and the weft yarn guide member 12 made of an electrically conductive material. Further, it is required that a relative movement between the weft guide member 12 and the guide channel 11 is present. Induced currents and / or the proper movement of the electrically conductive component create a magnetic field around the electrically conductive component, which interacts with the magnetic field of the magnetic component and exerts at least one upward magnetic force component on the weft guide element 12, which thereby extends at a distance above the Guide channel 11 is held. Conveniently, the relative speed between the weft guide member 12 and the guide channel 11 is selected such that the upward magnetic force component is equal to the force acting on the weft guide member 12 gravity, so that the weft guide member maintains a constant distance to this throughout its path over the guide channel 11.

Fig. 3 shows in detail the accelerating device 13 for the weft yarn guide element 12. The device 13 has a pneumatic cylinder 21, the piston rod 22 is movable against the rear end of the weft guide element 12 and thereby shoots in the shed. By means of a close to the cylinder 21 arranged pre-chamber 29, the rapid filling of the cylinder can be ensured. A fast-switching valve can release the air of the prechamber 29.

In Fig. 4, the weft selecting device 14 is shown in detail. This device 14 essentially corresponds to a weft selection device, as used for rapier looms. It has eight on a circular arc juxtaposed thread pliers 23.1 to 23.8 with eyelets 24.1 to 24.8. The thread tongs 23.1 to 23.8 are pivoted together on the circular arc, so that either each of the thread tongs 23.1 to 23.8 brought to the weft yarn transfer in selection position, d. H. can be positioned over the weft guide element 12. In the example shown, this is the thread tongs 23.8. This thread pliers 23.8 has also been pivoted from its selection position above the weft guide element 12 down, whereby a not shown here, between the eyelet 24.8 and the thread pliers 23.8 tensioned weft thread can be taken over by a clamping device 25 of the weft thread guide member 12. The clamping device 25 is preferably mounted so as to be displaceable along the weft guide element 12, so that it can always be positioned independently of the insertion direction of the weft guide element 12 into the shed at its head end.

It has two clamping jaws 15.1, 15.2, which pinch the weft guide element 12 laterally between them and thereby can decelerate. In the opened state, the clamping jaws 15.1 and 15.2 hold the weft guiding element 12 in the firing position until the piston rod 22 of the accelerating device 13 shoots the weft thread guiding element 12 into the shed. During the acceleration process by the piston rod 22, the clamping jaws 15.1, 15.2 serve to guide the weft thread guide element 12. For this purpose, the clamping jaws 15.1, 15.2 are provided with the shape of the weft guide element 12 adapted grooves 26,27 which guide the weft guide element 12 laterally and from below and allow from the top. The jaw 15.1 is also provided on the top with flow channels 28 for compressed air, with the the clamping device 25 of the weft guide element is moved to the head end 12.1. Thus, the weft thread from the weft selector 14 as close to the edge of the fabric can be transferred to the weft guide element 12, whereby the weft yarn drop can be minimized.

Claims (23)

Method for supporting a weft guide element (12) in the shed of a loom (10), characterized in that the weft guide element (12) is moved through the shed relative to at least one guide channel (11), the weft guide element (12) being magnetic and the guide channel (12) 11) is electrically conductive or the weft thread guiding element (12) is electrically conductive and the guide channel (11) is magnetic and wherein a magnetic force is exerted on the weft thread guiding element (12). A method according to claim 1, characterized in that the relative movement between the weft guide element (12) and guide channel (11) and the arrangement of the at least one guide channel (11) is selected such that an upward force component of the magnetic force is generated, preferably the same the force acting on the weft guide element (12) is gravity. A method according to claim 1 or 2, characterized in that by a corresponding shaping of the guide channel (11) and the weft thread guide element (12) acting on the weft thread guide member (12) magnetic force also has force components, the weft yarn guide element (12) during its flight through the Center the shed to the guide channel (11). Method according to one of claims 1 to 3, characterized in that in addition to the weft thread guide element (12) and the guide channel (11) forming components (16, 17) are moved. Method according to one of claims 1 to 4, characterized in that the weft thread guide element (12) is entered with a weft thread alternately from both sides in the shed. Weaving machine for carrying out a method according to one of claims 1 to 5, characterized by at least one of at least one electrically conductive or magnetic member (16, 17) formed guide channel (11) for at least one magnetic or electrically conductive weft yarn guide element (12). Loom according to claim 6, characterized in that the guide channel (11) is formed in cross-section at least approximately V-shaped. Weaving machine according to claim 6 or 7, characterized in that the guide channel (11) is arranged and designed such that it can perform proper movements. Loom according to claim 8, characterized in that the speed of the proper movements of the guide channel (11) is adjustable. Weaving machine according to one of claims 6 to 9, characterized in that the guide channel (11) of at least two mutually parallel bars (16, 17) is formed. Loom according to claim 10, characterized in that the rods (16, 17) are driven in rotation and / or oscillating and / or pivoting. Loom according to one of claims 6 to 11, characterized in that the guide channel (11) is divided in the longitudinal direction into a plurality of mutually insulated segments. Weaving machine according to one of claims 6 to 12, characterized in that it comprises on one or both sides of the shed an acceleration device (13, 13 ') for the at least one weft thread guide element (12). Weaving machine according to one of claims 6 to 13, characterized in that it comprises on one or both sides of the shed a weft selection device (14, 14 '). Weaving machine according to one of claims 6 to 14, characterized in that it comprises on one or both sides of the shed a braking device (15, 15 '). Accelerator device for a loom according to one of claims 6 to 15, characterized in that it comprises a pneumatic cylinder (21), the piston rod (22) against one end of the weft thread guide element (12) is movable. Acceleration device according to claim 16, characterized in that it comprises a tightly arranged on the pneumatic cylinder, can be filled with compressed air prechamber (29). Acceleration device according to claim 17, characterized in that the air of the pre-chamber (29) is releasable by means of a fast-switching valve. Weft thread guide element for a loom according to one of claims 6 to 15, characterized in that it comprises a clamping device (25) for a weft thread which is displaceably arranged from one end (12.1) of the weft thread guiding element (12) to the other end. Weft guide element according to claim 19, characterized in that the clamping device (25) is displaceable by means of compressed air. Weft guide element according to claim 19 or 20, characterized in that its underside has a cross-sectionally at least approximately V-shaped contour. Weft selection device for a weaving machine according to one of claims 6 - 15, characterized in that it comprises a plurality of juxtaposed on a circular arc thread tongs (23.1 - 23.8) with eyelets (24.1-24.8), which are arranged together pivotable on the circular arc. Weft-selecting device according to claim 22, characterized in that each of the thread tongs (23.1 - 23.8) with its thread eyelet (24.1 - 24.8) from a selection position on the weft guide element for thread transfer to this downwardly pivoted.

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