EP3186422B1 - Loom - Google Patents

Description

The invention relates to a weaving machine comprising a device for opening shed between adjacent warp threads, a weft insertion device for inserting at least one weft into all opened shed by means of at least one projectile pulling a weft, a reed with a plurality of reed teeth for attaching the inserted weft and a belt drive a belt which is guided around two pulleys, of which at least one belt region which extends linearly between the pulleys is arranged below the reed in the entry direction of the at least one weft thread, the projectile having at least one permanent magnet or ferromagnetic body with magnetic attraction being arranged by means of at least one permanent magnet guided by the belt can be pulled through the shed over horizontally oriented areas of the retina.

The invention further relates to a method for operating a weaving machine, in which at least one projectile with a weft thread by magnetically attractive interaction between the projectile, in particular at least one permanent magnet or a ferromagnetic body, which is attached to / in the projectile and at least one permanent magnet of a moving one Belt is pulled over horizontally aligned reed tooth areas of a reed through weaving compartments opened between warp threads.

A weaving machine of this generic type is, for example, from the patent DD 279700 A5 known. A loom according to the preamble of claim 1 is known FR 2333067 A known. In the loom of the known prior art, this becomes at least one permanent magnet projectile with magnetic attraction from a permanent magnet, which is arranged on the belt, pulled through the shed, wherein the projectile slides in the area of the shed over the aforementioned horizontal areas of the reed teeth.

The projectile glides outside the weaving compartments or the reed teeth over an area referred to in this publication as the rifle track and is returned via this rifle track from the end of the reed teeth or the weaving compartments following the belt movement back to the beginning of the weaving compartments or the back teeth.

The fact that the rifle track is spaced from the belt surface at every point of its extension inevitably means that the projectile sliding over this rifle track is at a distance from the belt and the permanent magnet moved by the belt at every location of its movement path. In this state of the art, the projectile has a constant distance from the belt surface along its entire trajectory.

This gives rise to the problem mentioned by the prior art mentioned that in the deflection areas in which the belt is guided around the pulleys, the projectile following this circular path has considerable centrifugal forces which would cause the projectile to move from the rifle path into the Would deflect.

In order to avoid this, it is provided in the cited prior art that a plurality of rollers is arranged in the deflection areas, i.e. surrounding the pulleys approximately semi-circularly, so that the projectile in these areas between the semi-circularly curved rifle track and the one around it arranged roles is performed. The roles here mean that the projectile cannot stand out from the rifle path due to the centrifugal forces acting. To slow down the projectile in To prevent this deflection area further, it is further provided according to the known prior art to actively drive the rollers with a further belt.

The construction mentioned makes the belt drive of such a weaving machine structurally complex and reduces the possibilities of further increasing the weaving speeds.

It is therefore an object of the invention to improve a weaving machine of the generic type mentioned at the outset in such a way that the construction is simplified, in particular that even higher weaving speeds can be achieved without having to fear the loss of a projectile due to acting centrifugal forces.

This object is achieved with the features of claims 1 and 10.

According to the invention the object is achieved in that in areas of the belt in which the belt is guided around pulleys, the projectile is moved with direct contact to the belt and by means of ramps, over which the projectile is pulled, the projectile between the belt surface and the surface of the horizontal back tooth areas to and fro.

The essential core idea of the invention is based on the fact that at least in areas in which the belt is deflected and has no straight linear extension, contact is made with the belt. According to the invention, such a contact exists at least in an environment around the location of the deflection of the belt, where maximum centrifugal force prevails, preferably at least over the major part of the deflection distance, that is to say the semicircular course of the belt around the belt pulleys. It can preferably be provided that in all areas of the movement of the projectile outside the reed or the opened shed and the ramps surrounding the reed, the projectile is in direct contact with the belt with magnetic attraction.

Compared to the state of the art, the rifle track mentioned there, on which a projectile is returned from the end of the reed teeth to their beginning, is completely eliminated.

The invention therefore realizes in areas outside the rivet teeth and outside the ramps that between the projectile, e.g. between at least one permanent magnet or a ferromagnetic body which is mounted on / in the projectile and at least one permanent magnet of the belt, the smallest possible distance is realized at least in the deflection area of the belt. This also means that the magnetic attraction between the permanent magnet of the belt and the projectile reaches the maximum possible strength. For example, neodymium magnets can be used as permanent magnets, or permanent magnets and ferromagnetic bodies with neodymium magnets or neodymium magnets with iron bodies.

Due to the lack of distance between the projectile and belt, at least in a local environment around the maximum centrifugal force, possibly in the entire deflection area, it is preferably ensured by suitable selection of the magnetic pairing of the projectile and belt and the rotational speed that the magnetic attraction force is always greater as the Centrifugal force that acts on a projectile in this deflection area. In these deflection areas, the projectile is therefore held in contact with the belt exclusively by the magnetic, attractive interaction between the permanent magnets of the belt and the projectile, without the need for a further device for preventing the loss of a projectile in these deflection areas.

In order to keep the centrifugal forces as low as possible, it can be provided that a projectile, in particular apart from the permanent magnet or magnetizable, preferably ferromagnetic body arranged therein / thereon, is of non-metallic design, e.g. made of a plastic or plastic composite, e.g. a plastic-fiber composite.

The invention further ensures that the ramps mentioned in front of and behind the ratchet teeth, in particular those with the highest ramp areas in each case directly adjoin these reed teeth, make it possible to change the height of the projectile relative to the belt, and thus the projectile through the Ramps can be safely raised to the height of the horizontal ratchet tooth areas with respect to the belt which is guided along these ratchet tooth areas, and in the same way at the end of the serrated tooth areas can be returned from this height to the belt until it comes into contact with it.

Preferably, only in the area of the ramps and in the area of the horizontal ratchet tooth areas, over which the projectile glides, the projectile is at a distance from the belt on its path of movement, which, however, is not critical in the present case, since only small forces tend to act in these areas, which tend to do so would further increase the distance between the projectile and the belt. These small forces, if any, are largely overcompensated for by the magnetic attraction between the at least one permanent magnet or magnetizable body of the projectile and the at least one permanent magnet of the belt.

In particular, despite this distance between the projectile and the belt, the magnetic attraction force is dimensioned so large that the projectile always safely follows the leading at least one permanent magnet of the belt and is thus pulled through the shed.

In a simple embodiment of the invention, this can provide that the respective ramps are designed, for example, as an inclined plane, that is to say as a flat surface that extends obliquely between the belt surface and the surface of the horizontal ratchet tooth regions.

Another embodiment can also provide that the ramp surface does not form a plane that is inclined to the horizontal, but that the start and / or end region of a respective ramp asymptotically adjoin the belt surface in its horizontal region or also in the curved region thereof that runs around the pulleys Area or to the surface of the horizontal rivet tooth areas. The effect of this is that a projectile is moved as smoothly as possible with only slight changes in the movement path between the different altitudes, that is to say between the belt level and the higher level of the horizontal rear tooth areas.

The invention can further provide that a weft thread to be inserted into the shed is transferred to the projectile before the projectile enters the shed or onto the horizontally aligned ratchet tooth areas and is then carried along by the projectile. For this purpose, the invention can provide that a thread feed device is provided in the area in front of the first ramp in the direction of movement or also above the ramp surface, which essentially provides a thread in such a way that a thread region to be fastened to the projectile crosses the path of movement of the projectile and by contact between it Thread end and the projectile one automatic transfer and attachment of the thread end to the projectile.

For this purpose, the invention can provide that the projectile has a clamping device into which the thread end to be taken over automatically gets in and is fastened therein. Such a clamping device can be designed, for example, as a clamping slot for the clamping reception of such a weft thread. Such a clamping slot can preferably expand forward in the direction of movement of the projectile, so that a thread is securely inserted into the clamping slot area when the projectile moves towards the thread end and is then securely clamped in the clamping slot by reducing the size.

In one possible embodiment, the invention can provide for the clamping slot to be formed, for example, by resiliently mounted clamping jaws or, in one embodiment thereof, also with elastomeric slot flanks.

In the weaving machine according to the invention, it can further be provided that a thread clamping device is arranged in the weft insertion direction after the reed, in particular one that is designed to be controllable, by means of which a weft thread drawn from the projectile can be clamped, in particular in a possible application due to the further movement of the projectile can be torn out of the projectile or its clamping device. Likewise, a thread clamping device can only be arranged in front of or additionally in front of the reed. According to the following description, a thread clamping device can also comprise a plurality of portions arranged around a reed.

In this way, a thread can be released from the clamp on the projectile and / or pulled taut during the projectile movement. Clamping such a device can therefore only be a tightening or braking, for example cause the thread and not necessarily pulling the thread out of its clamping or fastening to the projectile.

After the projectile weft thread has been released from the projectile, the projectile can be continued with its belt along its path of movement without conveying the weft thread. In this way, the projectile can be returned to its starting position, that is to the beginning of the reed and the thread feeding device there, without the weft being conveyed.

The thread clamping device can e.g. be triggered by a sensor system that interacts magnetically or electromagnetically, e.g. by interaction with the magnet or magnetizable body of the projectile, for example when the projectile flies past or flies through such a sensor system of the thread clamping device. For this, the sensors of the thread clamping device can e.g. have a magnetically activated or activated sensor, e.g. a reed contact or Hall sensor. The thread clamping device can also have a light barrier or other sensor system as a sensor system, which triggers the clamping or at least a tightening of the thread when the projectile flies through or flies past, in particular whereby the clamping or braking mechanism can be triggered immediately or after a predetermined time delay has elapsed.

The triggering sensor system of the thread clamping device can be locally separated from the clamping mechanism of the thread clamping device. A thread clamping device of this type thus comprises two parts that can be separated locally. For example, it can be provided to provide the sensor system after a reed, but the clamping mechanical part in front of the reed.

Regardless of the type of trigger sensor system and its specific local arrangement, it can be preferably provided that the clamping and / or Braking or tightening of the thread is triggered by the projectile itself, in particular thus such a thread clamping device does not have a rigid mechanical coupling causing the triggering to the drive of a weaving machine.

Such an embodiment with a thread clamping device can in particular be provided if a projectile with a continuously rotating belt drive is also continuously transported in only one direction of movement of the belt.

In principle, however, the invention can also provide that the belt drive is operated in a reversing manner, so that in order to form a real selvedge, a weft thread can in turn be passed through a newly opened weaving shed without detachment from the projectile on a return movement.

In order to achieve a transfer of a projectile that is as uniform as possible in the movement from the surface of the belt, on which it is guided in contact, to the surface of a ramp or from this back to the belt surface, the invention can further provide that the front of the projectile has a Has start-up slope, in particular which has a resilient flexibility.

For this purpose it can be provided, for example, that a projectile with the clamping device mentioned at the beginning has a sliding surface on its underside, for example as a spring plate, preferably non-magnetic spring plate, which is bent upward at its front end pointing in the direction of movement or is at least tapered upwards. For example, it can be provided here that at least one permanent magnet of the projectile is arranged between this front end and a clamping device, in particular a clamping slot of the projectile.

A supplementary development of the invention can also provide that, for example, the horizontally oriented areas of the seat teeth and / or the ramps and / or the projectile lower surface have a coating that reduces sliding friction.

In particular, the invention also provides that at least one permanent magnet is embedded in the belt material, in particular in such a way that a surface of the embedded permanent magnet facing the projectile does not protrude beyond the surface of a belt material. A magnetic surface facing the projectile can be flush with the belt surface for this purpose, but in particular at least one permanent magnet can also be enclosed on all sides by the belt material.

The weaving machine can also be operated in such a way that the belt drive is operated continuously in a revolving manner, as already described at the beginning, wherein several, in particular at least two projectiles are guided simultaneously by the belt drive, for which purpose at least in the belt, as described above, at least two permanent magnets or at least two arrangements of a plurality of permanent magnets are arranged in the circumferential direction of the belt, in particular evenly distributed.

For example, operation can take place in such a way that when a projectile has left the reed and in particular the downstream ramp, another projectile which is being conveyed simultaneously with the belt runs onto the ramp in front of the reed or already into the reed and the reversed weaving compartments after a reed attack occurs.

This enables a particularly fast and energy-efficient weaving operation, in which it only has to be ensured that between the exit of a projectile from the weaving compartments and the entry of a next projectile into the reversed weaving compartments, there is sufficient time for the removal of the entered one The weft thread from the projectile emerging from the shed, the reed stop, the shed reversal and thread feed to the next projectile remain.

A preferred embodiment of the weaving machine according to the invention is explained in more detail in the following figures.

This is illustrated in a view of a weaving machine according to the invention, which is limited to the belt drive and the reed, without showing the warp beam and the warp threads Figure 1 that a belt 2 guided around two pulleys 1 carries at least one permanent magnet 3 in the circumferential direction of the belt. This permanent magnet 3 can preferably be completely embedded in the belt so that it does not protrude beyond the belt surface, in particular its surface is covered by belt material.

A linearly extended region 2a of the belt 2 between the pulleys 1 runs below the ratchet teeth and parallel to the weft insertion direction.

A projectile 4a of several projectiles 4a, b, c which are guided at the same time and which also has at least one permanent magnet or a magnetizable, e.g. Ferromagnetic body 12 is carried under magnetically attractive interaction between the respective magnetic partners in the direction of movement of the belt 2 and in contact with the belt 2.

The Figure 1 shows a position of the projectile 4a in the deflection area of the belt 2 in the case of the pulley 1 arranged here on the left.

When moving in the direction of the reed 5, the projectile 4a reaches a ramp 6a arranged in the direction of movement in front of the reed 5, which bridges the height difference between the belt surface and the reed surface. By moving the projectile 4a in attractive interaction with the Belt 2 accordingly transfers projectile 4a to the surface of the ramp and pulls it up on ramp 6a at the beginning of the reed. Here, a weft thread is fed from a weft yarn spool, not shown, to a clamping device 11 of the projectile 4a and, for example, clamped in the projectile 4a.

On its further path, the projectile 4a is carried out with the magnetic interaction with the at least one permanent magnet 3 of the belt 2 continuing via the horizontally oriented rivet tooth regions of the reed 5 and, accordingly, according to the usual structure of a weaving machine, through the opened shed between the warp threads. This is shown in the lower part of the Figure 1 for the projectile 4a.

As soon as the projectile 4a, which is magnetically guided through the weaving compartments, has left the weaving compartments and the surface of the horizontal ratchet tooth areas, it arrives in the direction of movement after the reed 5 on a further ramp 6b and is thereby returned from the height position of the rivet tooth surface to the height position of the belt 2, so that the projectile in turn contacts the belt 2 directly after the ramp 6b, as at the beginning of its movement.

Figure 1 Above shows the position of the projectile 4b at the end of the ramp 6b, which follows the reed 5 in the direction of movement. According to the invention, it can be provided here that a device (not shown) for clamping the weft thread is removed from the projectile so that the projectile 4 without further conveying the weft thread in the direction of movement of the belt, here in particular all around the pulley 1 at the beginning can be traced back to its movement. This is the situation Figure 1 below for the projectile 4b.

It is particularly important here for the invention that at least in a part of the deflection area, possibly in the entire deflection area of the belt 2 around the pulley 1, in which the projectile of a semicircular path in passes through its movement, this projectile is in contact with the belt and is thus guided with the smallest possible distance between the respective permanent magnets, so that the projectile 4 can be returned to its starting position without loss of the projectile due to the acting centrifugal forces.

The Figure 1 makes it clear that not only one permanent magnet 3 is provided in the circumferential direction of the belt 2, but rather a plurality of permanent magnets 3 or, alternatively, a plurality of permanent magnet arrangements comprising a plurality of permanent magnets, so that a plurality of projectiles 4a, b, c rotate simultaneously in the weaving machine during the movement of the belt 2. Of course, the weaving machine can also be operated with only one projectile, two projectiles or more than the 3 projectiles shown here.

Due to the movement of several projectiles 4 at the same time, a particularly short chronological sequence between the entries of the respective weft threads in the weaving compartments of the warp threads can be achieved without having a complete return of a projectile 4 along its movement path to the beginning of the reed 5 for a subsequent weft thread entry needs to be serviced.

It should be noted that the weaving machine according to the invention can also be operated reversibly with only one projectile, e.g. to feed a single weft back and forth to form a real selvedge.

The Figure 2 also shows possible designs of a projectile 4 of a weaving machine according to the invention.

The symbolized representations of this projectile 4 make it clear that it has a sliding surface 9 in a lower region, which has a run-up slope 10 at its front end 9a in the direction of movement. Such a sliding surface 9 can, for example, also be formed by a Spring plate, the front end of which is bent upwards, the term spring plate not necessarily implying that it is made of metal. Rather, it can be provided here that such a spring plate is made of a non-metallic, or at least non-magnetic material.

At the rear end of the sliding surface 9 in the direction of movement, a projectile according to the invention provides a thread holder, which can be designed, for example, as a thread clamping device 11. According to the Figures 2A and 2B the thread clamping device has a slot 11a which is open to the front in the direction of movement and in which a weft thread 8 can be inserted transversely to the direction of movement of the projectile 4 by means of a thread feeder.

Due to the movement of the projectile 4, a weft thread 8 fed in this way automatically enters the shrinking slot area of such a clamping device and is securely held. In the direction of movement in front of the thread clamping device or generally a thread holder 11, the invention provides here that at least one permanent magnet 12 is arranged, which forms the magnetic attractive coupling to the at least one permanent magnet 3 of a belt of the figures discussed previously. Instead of a magnet 12, a magnetizable body can also be used.

In particular, the run-up slope 10 of the sliding surface 9 of a projectile 4 designed according to the invention further ensures that a very smooth, secure movement between such a projectile 4 from its position contacting the belt to a ramp 6a / 6b and back is ensured. In addition, such a bevel 10 also ensures that the projectile 4 glides safely over the individual spaced horizontal areas of the rivet teeth on its way through the shed.

By a corresponding length of the sliding surface, which preferably corresponds to at least four times the distance between two adjacent ratchet teeth furthermore ensures that the projectile 4 moves in the area of the reed in such a way that jumping of the projectile 4 is avoided.

Figure 2C shows an alternative embodiment in which a thread 8 can be clamped between a spring-loaded punch 11b and a stop 11c. Here, the punch 11b is arranged on one of the two ends of a two-armed lever, the other end of which is spring-loaded and which is pivotably mounted between the ends.

Figure 3 visualizes different versions of ramps 6. Figure 3A shows the already in Figure 1 shown ramp 6 with an inclined plane. In contrast, the ramps of the Figures 3B and C in each case start and end areas which asymptotically approach the tangent of the belt surface and reed surface, the tangent here in each case corresponding to a horizontal. There would also be the possibility to approach a tangent of the belt in its curved area. Figures 3B and C differed only in that in Figure 3B between the curved asymptotic areas has a flat area, whereas in Figure 3C the curved shape is directly merging between the two areas.

Figure 4 shows the execution of a reed 5 under which the belt 2 runs along. The reed here has a horizontally running rivet tooth area 5a, which forms the running surface of the projectile. This horizontal area can form a groove 5b in the weft insertion direction through material cutouts in each tooth. The tread may have a coating that reduces sliding friction. A weaving shed 14 opened between two warp threads 13 can also be seen here. The inserted weft thread 5c strikes the inserted weft thread by pivoting the reed about its axis of rotation 15.

Claims (10)

1. Loom comprising a device for opening sheds between adjacent warp threads, a weft-insertion device for inserting at least one weft thread into all opened sheds by means of at least one projectile (4) which pulls a weft thread, a reed (5) having a plurality of reed dents for beating up the inserted weft thread (8), and a belt drive having a belt (2) guided around two pulleys (1), of which belt at least one belt region (2a) extending linearly between the pulleys (1) is arranged below the reed (5) in such a way that said at least one belt region extends in the insertion direction of the at least one weft thread (8), wherein the projectile (4), which comprises at least one permanent magnet or at least one magnetizable body (12), can be pulled through the sheds across horizontally arranged reed detent regions under magnetic attraction by means of at least one permanent magnet (3) guided by the belt (2), and wherein a ramp (6a) is arranged before the reed (5) in the weft insertion direction, by means of which ramp a projectile (4), carried on the belt (2) in a contacting manner, can be lifted off the belt (2) against the magnetic attraction force during the motion of the projectile in the direction of the reed (5), and a ramp (6b) is arranged after the reed (5) by means of which ramp the projectile (4) can be led back onto the belt (2), characterized in that on the one hand, the ramps (6a, 6b) are arranged with respect to the reed in such a manner that the projectile (4) switches back and forth between the belt surface and the surface of the horizontal reed dent region, wherein on the other hand, the projectile (4) can be lifted off the belt (2) against the magnetic attraction force up to the height of the horizontally oriented reed dents during the motion of the projectile in the direction of the reed (5) in order to transfer the projectile (4) from the ramp (6a) to the surface of the horizontal reed dent region.
2. Loom according to claim 1, characterized in that at least one of the ramps (6a, 6b) is formed as an inclined plane or having a start and/or end region asymptotic to a tangent of the belt surface or of the surface of the reed dents.
3. Loom according to any one of the preceding claims, characterized in that a projectile (4) has a clamping slot (11a) for clamping reception of a weft thread (8).
4. Loom according to claim 3, characterized in that the clamping slot (11a) is formed by spring-loaded clamping jaws or by elastomeric slot flanks.
5. Loom according to any one of the preceding claims, characterized in that the front of the projectile has a run-up slope (9a), in particular the run-up slope has a springy resilience.
6. Loom according to any one of the preceding claims, characterized in that an in particular controllable, in particular magnetically-controlled thread clamping device is arranged in the weft insertion direction after and/or before the reed (5), by means of said thread clamping device a weft thread (8), pulled by the projectile (4), can be clamped, in particular can be torn out of the projectile (4) or can at least be pulled taut.
7. Loom according to any one of the preceding claims, characterized in that the horizontally oriented region of the reed dents and/or the ramps (6a, 6b) and/or the surface of the underside of the projectile have a coating to reduce sliding friction, or the projectile is manufactured from a material which has a low friction coefficient during contact with the surfaces of the reed dents and/or the ramps.
8. Loom according to any one of the preceding claims, characterized in that at least one permanent magnet (3) is incorporated into the belt material, in particular is enclosed by belt material on all sides.
9. Loom according to any one of the preceding claims, characterized in that the belt drive is continuously driven in a circulating manner, in particular, it hereby guides at least 2 projectiles (4) simultaneously.
10. Method for operating a loom, in particular a loom according to any one of the preceding claims, in which at least one projectile (4) with a weft thread (8) is pulled through sheds opened between warp threads by a magnetically attractive interaction between the projectile, in particular between at least one permanent magnet applied on the projectile (11), or between a magnetizable body (12) applied on the projectile (11) and at least one permanent magnet (4) of a moved belt (2) across horizontally oriented reed dent regions of a reed (5), characterized in that in regions of the belt (2), in which the belt (2) is guided around pulleys (1), the projectile is moved by direct contact with the belt and by means of ramps (6a, 6b), over which ramps the projectile is pulled, the projectile switches back and forth between the belt surface and the surface of the horizontal reed dent region, wherein the projectile (4) can be lifted off the belt (2) against the magnetic attraction force up to the height of the horizontally oriented reed dents during the motion of the projectile in the direction of the reed (5) in order to transfer the projectile (4) from the ramp (6a) to the surface of the horizontal reed dent region.

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