EP0741808B1 - Controllable output brake, thread feed device as well as projectile or gripper weaving machine - Google Patents

Description

The invention relates to a controllable outlet brake according to the Preamble of independent claims 1 or 2, a projectile loom according to the preamble of claim 12, and a rapier loom according to the preamble of the claim 13.

A controllable outlet brake on the storage drum of a thread delivery device is for projectile or rapier weaving machines known to limit the balloon when entering and a To allow thread control. It is the outlet brake on Very little strain on the thread starting at the beginning of the entry, especially with regard to the dreaded stroke and at sensitive thread qualities, possibly with low thread quality, and only during the entry the thread tension increase. However, this is exactly reproducible and quickly appealing, i.e. changes within a few milliseconds Braking effect required. These requirements have been around for more spout brakes known as 20 years in the modern Looms of this type are usually high thread speeds not satisfactorily.

An example is the end brake according to US-A-3 411 548, at the guide elements protruding outwards from the support ring into oblique slots of the crescent-shaped holding member engage. The adjustment drive has a cam drive for rotating the Support ring around the drum axis and relative to the holding member. During the rotary movement, the support ring becomes dependent on the direction of rotation moved forward or backward through the slots to reduce braking to change in operation. Relatively large, quickly moving masses, energy-consuming movements, unstable end positions the support ring, etc., are reasons why this well-known Principle is not used in modern weaving machines.

Another outlet brake is from GB-A-13 55 518 for a projectile weaving machine known. A rigid balloon cone is axially in the stationary holding member between a slight braking position and an open gap position can be moved back and forth. An annular armature of a magnetic actuator is attached to the cone, against the cone when the coil is energized a return spring from the gap position to the braking position pulls. Large moving masses, a relatively coarse or sluggish braking effect and a delayed response are reasons why this outlet brake in modern Weaving machines of this type are no longer used.

A modern controllable outlet brake according to the preamble of claims 1 and 2 is from FIGS. 6 and 7 WO91 / 14032 known. The frustoconical support ring is in the inner circumferential surface of the annular holding member is mounted such that it can be tilted, and that in a formed from openings and webs, Line concentric to the axis of the storage drum. in the The tilting area is the support ring without any significant axial play set in the holding member. The support ring has in both Tilt directions around the tilt line in the holding member more space Available as needed for its adjustment. The free one inner end region of the thread braking element lies on the braking surface the storage drum under the action of a in the holding member behind the support ring, the actuator, e.g. an inflatable or inflatable, in the circumferential direction in the holding member running hose. The hose is via the drive control with compressed air or another Medium more or less fillable and determines the tilt position of the support ring the size of the pressing force on the braking surface. The resetting of the support ring in order to reduce the pressing force takes place via the elasticity of the thread braking element even because the actuator has only one direction of action. The Tilting of the support ring is due to its truncated cone shape a deformation of the relatively dimensionally stable truncated cone and thus very high actuation forces on the part of the actuator. A controlled increase in pressure is therefore only has a delayed effect and its extent can hardly be predicted exactly. When the pressure force is withdrawn, the support ring displaces the medium from the actuator. Since the tipping position of the Support ring by means of the pressure in the elastic actuator is adjustable and limit stops for the support ring are missing, no exactly reproducible tilt positions are possible. With This outlet brake can meet the requirements for an exact Do not perform thread control satisfactorily.

The invention has for its object a controllable outlet brake and a projectile and a rapier weaving machine easy to design so that even at high thread speeds exact weft control is given, or to ensure that the controllable outlet brake the use the high possible in modern weaving machines of these types Thread speeds even with sensitive thread qualities enables.

This object is achieved with the features of the patent claim 1, the independent claim 2, the claim 13 or claim 14.

When adjusting the thread brake element in the respective direction of movement need the shortest route and without energy-consuming Deflections only small masses to be moved. This leads with the help of the compressed air medium and for everyone Sliding drives provided, and thanks to the pneumatic drive control, for exactly reproducible, precisely controllable quick response, so that the outlet brake for example in a few milliseconds, e.g. 15 Milliseconds, release or indent. The compressed air builds not only the required pressure quickly up and down, but generates relatively high forces with high operational reliability for positioning the thread brake element in the respective Position. Compressed air is on the weft feeder or the loom, is environmentally friendly and powerful. The concept is structurally simple and user-friendly and individually to the respective circumstances tunable. The quick response due to the pneumatic Actuation and the small moving masses is favorable because the outlet brake only very shortly before the start of the entry and not is opened long before, so the thread is not too early can be released, and because during the entry as well quickly closed and, if necessary, opened again immediately becomes what an exact adjustment with the rapier weaving machine to the handover phase and at the projectile machine avoiding a delay in projectile flight (none Deviations from the predetermined arrival time). Completely unexpected, even at high thread speeds the voltage peak that was previously indispensable the drawing stroke in the thread in the initial phase extremely minimize the entry or completely avoid what the thread breakage rate is drastically reduced. The efficiency Modern weaving machines of this type are pneumatic actuated outlet brake on the storage drum too fully usable for sensitive inexpensive thread qualities.

The support ring is expediently linear and parallel to the axis the storage drum is moved by a sliding drive, to get to the new position quickly and exactly, in the thread braking element with the thread tension set in advance brakes or almost no braking effect causes.

Alternatively, is held stationary in the holding member Support ring of the middle section of the thread braking element by means of the sliding drives are deformed axially. This is assembly technology cheap because the thread braking element in the usual way can be easily replaced.

The exact positioning of the cooperating with the braking surface Thread brake element is in a further embodiment made by means of the ring element, which thanks to the pneumatic actuation works quickly and in the release position can pull the thread largely unhindered. In the In the passive position, the ring element influences the braking function Not.

One actuated from the pneumatic drive control Piston is reliable even over long periods of use.

It is useful to have both sliding drives with pneumatically working Equip pistons that work alternately.

Alternatively, oppositely acting pistons with different Actuation areas act, what the control simplified.

An embodiment is structurally simple in which the Tragring itself forms the piston that in one or in both Direction of movement is pneumatically applied while doing so is guided in the holding member.

Alternatively, to simplify construction, piston-like ones can also be used Extensions on the support ring are used to determine the number of Keep parts as small as possible.

In one embodiment with a return spring Tragring quickly reset appealing, since the in the opposite direction effective compressed air via the pneumatic drive control is suddenly relaxed. By the return spring compressed air energy is saved.

It is particularly expedient to provide ring contact areas so that an exact centric in both positions of the ring Positioning is achieved. The sliding drives have just task the ring as quickly as possible from one position to move into the other and the ring on each Position the investment area. The positioning is, however, taken over by the investment areas. this makes possible the use of simple and therefore more reliable Sliding drives.

In a user-friendly embodiment the at least one sliding drive body from the removal path of the thread brake element to remove it if it is worn and / or quick and easy to replace if necessary. The removal side of the holding member expediently points to Front end of the storage drum, where unobstructed access is possible is.

Is the return spring in the at least one sliding drive body then it is particularly useful to arrange a support surface in the holding member such that when Swiveling the sliding drive body into the removal position the preloaded return spring automatically and in preloaded State is intercepted. After inserting a new one Thread brake element and swiveling back the sliding drive body the return spring returns automatically in their active position on the ring. In addition, when exchanging by the return spring supported on the support surface Sliding drive body locked locked.

There are several for a tilt-free and quick adjustment Sliding drive pairs distributed in the circumferential direction on the holding member. The pneumatically operated sliding drives can be activated a common compressed air supply must be connected. It But it is also conceivable to have a separate one for each slide drive Compressed air supply with its own control valve to provide a relatively large amount of compressed air for each sliding drive to be able to provide or relax quickly.

The controlled outlet brake with a arranged in the support ring with an annular membrane an uninterrupted counter braking surface. The membrane forms a built-in radially and axially elastic spring in the Thread braking element, resulting in a desirable self-compensation effect of the outlet brake, i.e. the thread tension only slightly with increasing thread speed or not increasing at all and therefore a relatively high one Basic thread tension can be set, which is the case with both Types of weaving machines in question here are the important ones Advantage that the previously often downstream Thread delivery device provided multi-disc brakes for increasing thread tension can be omitted, their influence in Stretching is undesirably strong. The relatively high basic thread tension thanks to the pneumatically operated Sliding drives removed or eliminated when during no significant thread tension required for an entry is.

Alternatively, the thread braking element can also be a so-called Brush, tooth or lamellar ring with single or elastically deformable brake elements grouped in groups and a discontinuous circumferential braking surface be, its physical with increasing thread speed Conditional increase in thread tension or increase in braking effect then by means of the pneumatically operated sliding drives is eliminated or significantly weakened if this occurs in a certain entry phase is not desirable.

In a projectile weaving machine with a web cycle controlled Thread brake downstream of the thread delivery device and a pneumatically adjustable outlet brake on the storage drum exact thread control can be achieved, when both brakes work roughly synchronously. A leading one Apply the outlet brake on the storage drum rapid response to stabilize the thread between the Storage drum and the controlled thread brake without the To influence projectile flight noticeably. It can be done strictly adhere to the predetermined arrival time of the projectile, without the flight speed on harmful to the thread Way to increase.

In a rapier weaving machine with a rapier and slave rapier can previously required multi-disc brakes downstream of the thread delivery device omitted. Nevertheless, an optimal one Thread tension control over each entry to control faults when the bringer gripper starts moving, in the handover phase and to avoid at the end of the entry.

For projectile weaving machines and rapier weaving machines with this The drawing stroke can be equipped with the thread delivery device largely or even completely at the beginning of the entry avoid what sensitive thread qualities, e.g. Woolen or Cotton threads of inexpensive, low quality extraordinary is important because this is with modern weaving machines these types possible high thread speeds and without the high that was previously indispensable Thread breakage rate can be processed. There is also a more desirable one Cleaning effect with that used for drive control Compressed air in the thread delivery device because the relaxed or discharged compressed air removes fluff and impurities or not at all inside the thread delivery device lets get.

Fig. 1

eine Seitenansicht, zum Teil im Schnitt, einer Fadenliefervorrichtung für eine Projektil- oder eine Greiferwebmaschine, in einer Betriebsstellung,

Fig. 2

einen Detailschnitt zu Fig. 1, in einer anderen Betriebsstellung,

Fig. 3 und 4

eine andere Ausführungsform, zum Teil im Schnitt, in zwei unterschiedlichen Betriebsstellungen,

Fig. 5

einen Teil einer Frontansicht zu den Fig. 3 und 4,

Fig. 6

eine Teilschnittansicht einer weiteren Ausführungsform in einer Betriebsstellung,

Fig. 7 und 8

zwei weitere Ausführungsvarianten, im Schnitt,

Fig. 9

schematisch ein Schußfadenverarbeitungssystem einer Projektilwebmaschine,

Fig. 10

schematisch ein Schußfadenverarbeitungssystem einer Greiferwebmaschine,

Fig. 11

ein Betriebsdiagramm zu Fig. 9, und

Fig. 12

ein Betriebsdiagramm zu Fig. 10.

Embodiments of the subject matter of the invention are explained with the aid of the drawing. Show it:

Fig. 1

2 shows a side view, partly in section, of a thread delivery device for a projectile or a rapier weaving machine, in an operating position,

Fig. 2

2 shows a detail section of FIG. 1 in a different operating position,

3 and 4

another embodiment, partly in section, in two different operating positions,

Fig. 5

part of a front view of FIGS. 3 and 4,

Fig. 6

2 shows a partial sectional view of a further embodiment in an operating position,

7 and 8

two other versions, on average,

Fig. 9

schematically a weft processing system of a projectile loom,

Fig. 10

schematically a weft processing system of a rapier weaving machine,

Fig. 11

an operating diagram of FIG. 9, and

Fig. 12

10 shows an operating diagram for FIG. 10.

1 and 2, a thread delivery device F of a type known per se a stationary storage drum 1 on which a plurality of thread turns 2a - 2n for Formation of an intermediate supply or a reserve of a thread Y can be wound up. That of a supply spool, not shown coming thread Y is through a hollow, by means of a Not shown electric motor drivable in a motor housing 3 Drive shaft of the thread delivery device supplied and by means of a hollow one, with the drive shaft for rotation drivable arm (not shown) on the storage drum 1 brought.

The thread delivery device F is between the one not shown Supply spool, from which the thread Y through the thread delivery device is processed, and a textile machine (not shown) arranged. The textile machine is consuming the thread Y as a weft for weaving, knitting or around others Way to produce a textile product. Will the thread delivery device F used to deliver a weft for one Weaving machine to get into the Weaving machine corresponding to a plurality of thread turns 2a - 2n Subtract thread amount by means of entry of the weaving machine, then the thread Y is withdrawn from the thread reserve. The string Y is entered by the weaving machine Storage drum 1 in the axial direction via a trigger edge 4 deducted the storage drum, which is preferably slightly rounded is, and runs downstream through a coaxial to the storage drum 1 axially arranged trigger eye 5. Depending on the type of Loom Y can be controlled by a free-standing, controlled or alternatively non-controlled thread brake (not shown) be performed, and / or by a thread take-up device (take-up device). These two groups of components are known for themselves. This is the case, for example, when the thread delivery device F is used for delivery from thread Y to a projectile loom in which the weft with each shot by means of a projectile-like gripping member is transported through the shed.

In a boom 6 extending from the motor housing 3 is in the Thread delivery device F a carriage (not shown) axially slidably arranged, the an annular holding member 7th for an OYB outlet brake.

The annular holding member 7 carries a thread braking element in FIGS. 1 and 2 8, recently on the market under the name "Flexbrake" was introduced and essentially a truncated cone Circular ring or a frustoconical band made of elastic material, preferably rubber. Because of the training and arrangement forms the annulus of the Thread brake element 8 an uninterrupted in the circumferential direction or continuous investment line or investment area for investment against the rounded trigger edge 4 of the storage drum 1. The Trigger edge 4 also forms a rotationally symmetrical Braking surface 4 'for a counter braking surface or counter braking line defining contact line of the circular ring 8.

The circular ring of the thread brake element 8 is on its inner, "Braking active" inner area 8a with a thin Cover made of a material that is resistant to thread friction provided, for example from a metal or a metal alloy, expediently a stainless steel or one Beryllium copper alloy. The brake-active interior or the coating of the thread brake element 8 is characterized due to considerable axial stiffness and remarkable Flexibility or elasticity in the radial direction and due to preferably low inertia (mass). The annulus of the thread braking element 8 is in its the annular holding member 7 assigning area with or in a central section 8b with one or more circumferential "corrugations" formed to increase the elasticity of the middle section 8b increase. The central region 8b of the thread braking element 8 is attached in a support ring 9 inside, which in turn from annular holding member 7 is included.

An operator can select the axial position determine the force of the carriage (not shown) in the boom 6, with which the thread braking element 8 on the trigger edge 4 (or the braking surface 4 ') of the storage drum 1 is present. The operator can thereby create a "basic tension" the thread Y receives when it is pulled off from the storage drum 1 between the brake-active inner area 8a of the thread braking element 8 and the rounded Trigger edge 4 passes through.

The new type of runout brake has in particular to provide of favorable thread tension conditions during each Entry process in a weaving machine is very advantageous and proven positive properties. This outlet brake has a self-compensation effect insofar as the Tension in the thread downstream of the outlet brake with increasing Thread speed does not increase appreciably.

Despite this positive, with the outlet brake this in itself known type of achievable conditions it has been shown that there is a need for the thread tension at the outlet of the thread storage device F to control from "outside", taking it it is expedient to set the thread tension between a predetermined given thread tension level and practically a zero tension level or a voltage level at a low level to control back and forth.

Among other things, it is an object of the invention to provide a solution for propose these problems with which the desire for one uncomplicated setup with the smallest possible number of required Components can be met.

According to the invention in FIGS. 1 and 2, the thread braking element 8 arranged so that it can be moved in a controlled manner in the axial direction is such that its brake-active inner area is a Number of, expediently two, positions in relation can take to the rounded trigger edge 4. Preferably, however not exclusively, the thread braking element is arranged so that there is a first axial position (corresponding to Fig. 1) occupies in which its brake-active interior "normal" with a certain, preselected force against the trigger edge 4 (or the braking surface 4 ') is present. This force is predetermined by the axial position of the carriage (not shown). A certain, preselected result results from this force Tension in the thread. The thread braking element is also so arranged that there is a second axial position (as shown in FIG. 2) is able to occupy, in which the brake-active inner area 8a of the thread braking element 8 is "released" from the trigger edge 4, i.e. is no longer in contact with the trigger edge 4. This means in principle that the thread through the gap between to go through the thread brake element and the trigger edge 4 "freely" can As a result, the thread tension drops to a low one or in any case significantly lower level than it with the thread braking element 8 in its first axial position given is.

The controlled axial displacement of the thread brake element 8 can be implemented in several ways. In one embodiment is the support ring 9 axially within the holding member 7 arranged movably, for example by selecting its Extent in the axial direction. A first pneumatic cylinder 10 with a piston 10a is provided to with the rear end face or the rear edge of the support ring 9 to cooperate. A second pneumatic cylinder 11 with a piston 11a is provided to be in contact with the front face or the front edge of the support ring 9 and one Base part 8c of the thread braking element 8 cooperate. The first cylinder 10 is directly connected to a compressed air source CAS connected, whereas the second cylinder 11 with the same Pressure source via a three-way solenoid valve 12 of a known Construction is connectable. (There is another one here Use type of solenoid valve, if necessary in combination with modifications to the associated compressed air circuit.) A control unit (not shown) is electrically connected to the Valve 12 connected and suitably designed so that it controls the valve 12 synchronously with the textile machine, which is supplied by the thread delivery device F. That is, that in the case of a weaving machine, the control is synchronous with the Weaving cycle takes place, preferably in accordance with a desired appropriate thread tension during respect Phases of the weft insertion cycle, such as the acceleration phase, the "flight phase", the delay phase, etc.

In the functional description of the embodiment shown is started in the operating position of Fig. 1. In this Operating position, the control unit holds the solenoid valve 12 in its inactive status, whereby the piston 11a in second cylinder 11 remains in its left end position. There the first cylinder 10 is directly connected to the compressed air source CAS the piston 10a always strives to its right End position. However, the power is on in this starting position the support ring 9 and consequently also on the thread braking element 8 as a whole, which is exerted by the piston 11a, larger than that Force of the piston 10a, due to the fact that the piston 11a a larger cross-sectional area or loading area than the piston 10a has. This means that the thread braking element 8 with its support ring 9 in the left, "rear" Is or occupies a working position, i.e. the brake active Position. As soon as the control unit solenoid valve 12 then actuated, the piston 11a becomes its right end position take because the pressure on the cylinder 11 stops, while the cylinder 10 continues to be pressurized remains. As a consequence, the support ring 9 and thus also the thread brake element 8 offset to the right in the "front" position, i.e. in the brake inactive position, in which the thread braking element 8 is released from the trigger edge 4.

The stroke of the axial displacement movement of the thread brake element 8 with its support ring 9 need not be more than be a few millimeters to get the function you want or to get the result. The time for "switching" or moving the thread brake element between its Working positions can be in the described embodiment is approximately 10-15 milliseconds.

The axial displacement of the thread brake element 8 could different ways, e.g. by means of electromagnets or solenoids that attack directly on the carrier ring 9, or alternatively by means of displacement devices with piezo crystal elements can be controlled (since the necessary switching movement is so small), or with other known types linear adjustment devices.

To simplify the description is in the embodiment shown only a pneumatic transfer unit (Cylinders 10 and 11) shown. It should be emphasized that the Number of such units expediently at least three should be, and that these units be uniform around the perimeter of the thread brake element are distributed to a sufficient Homogeneity and speed when moving the thread brake element ensure.

It is also possible, but with the disadvantage of one to accept somewhat more complicated device that Number of "working positions" of the thread brake element too increase by more than two different thread tension levels to achieve. In the case shown, it is in principle just an "on and off function".

3, 4 and 5 is different Embodiment of a pneumatically operated outlet brake OYB in the holding member 7 on the boom 6 of the thread delivery device intended. The axial basic setting of the holding member 7 and thus the basic setting of the thread tension when the outlet brake is engaged by a with the holding member 7 connected slides 22 selected in guides 24. The carriage can be moved by means of an adjusting member 23; however, it is stationary during operation. The holding link 7 is to the removal side E (to the front end of the storage drum 1) open and shows recordings distributed over the scope 16 for sliding drive body 14, either together or individually between a stop position (in extended position Lines drawn) and a removal position (in 5 indicated by dashed lines) can be moved back and forth, preferably around a retaining screw parallel to the axis 15. In the holding position, each sliding drive body engages behind 14 the support ring 9 of the thread braking element 8 ', which in 3 - 5 a so-called bristle ring with flexible bristles or tufts of bristles that are preferably oblique inclined front support ring 9 extend inwards and an elastic deformable middle section 8b 'and an inner Define the brake-active inner area 8a 'as the counter-braking surface cooperates with the braking surface 4 'at the trigger edge 4. In the holding member 7 are two oppositely acting Sliding drives 10 ', 11' arranged. The sliding drive 10 ' contains the piston in a sliding guide or chamber 12 ' 10a ', for the purpose of better sealing and clean Guide is guided in a sliding sleeve 13 and from the pneumatic drive control 12 (see Fig. 1) with compressed air can be acted upon or relieved. Forms in the holding member 7 a radial surface a first ring contact area 20, which in the axial direction a contact area 21 on the sliding drive bodies 14 is opposite. The distance between the Investment areas 20 and 21, e.g. by 2 to 4 mm, larger than the axial width of the ring 9 of the thread braking element 8 '. The Piston 10a 'can be extended via the first contact area 20. In each sliding drive body 14 there is an axially arranged one Return spring 19 salvaged in a recess, which, preferably, applied to the support ring 9 via a piston-like sleeve 18. The return spring 19 is biased and over the second system area 21 extendable. The recording 16 for the Sliding drive body 14 is dimensioned so large that the sliding drive body 14 after rotation around the retaining screw 15 the removal path of the support ring 9 is moved out. After twisting the thread braking element of all sliding drive bodies 14 Lift out 8 'to removal side E and through new or another thread braking element (such as the thread braking element 8 according to Fig. 1) replace. More, for this one Thread brake elements that can be used are so-called toothed rings, the elastic teeth projecting inwards in the support ring 9 made of plastic or another material (similar to one annular comb), or a multi-disc brake ring, the In the support ring 9 inwardly protruding sheet metal or plastic lamellae wearing. Provided that the aforementioned Thread brake elements have approximately the same outside diameter of the support rings 9, they can be optionally against each other replace.

In the receptacle 16 is a support surface 17 for the return spring 19 provided, in such a way that they are about the height of the rear face of the support ring 9 is when this is pressed onto the first contact area 20. Thereby is achieved that when rotating each sliding drive body 14 for the purpose of removing the respective thread brake element the biased return spring 19 or the sleeve 18 on the Support surface 17 slides on without the return spring 19 could relax. By the force of the return spring 19 on the support surface 17, the sliding drive body 14 in the position of removal automatically secured. Is a new one or other thread braking element properly inserted, then is after turning back the sliding drive body 14 after as before biased and retracted return spring 19th moved back to the support ring 9. Once it is off the support surface 17 is released, the slide drive 11 'is again functioning.

3, the piston 10a 'is not acted upon pneumatically. The return spring 19 hold the support ring in contact with the first System area 20. The outlet brake OYB works with the system pressure set by the position of the carriage 22.

Each piston 10a 'comes from the pneumatic drive control 12 pressurized, then the support ring 9th abruptly against the force of the return spring 19 on the axially displaced second contact area 21, expediently the braking active inner area 8a 'the braking surface 4' only weak or not touched at all. This operating position is indicated in Fig. 4. Conveniently each sliding drive body 14 is in the holding position secured by tightening the retaining screw 15. But it would be also conceivable to provide an automatically acting latching here. It is also possible to move the support ring 9 between the first and second investment areas 20 and 21, e.g. by inserting or removing of washers between the slide drive body 14 and the holding member 7. There could also be two pneumatically acted upon pistons as provided in Figs. 1 and 2 his.

In the embodiment of the controllable outlet brake OYB the storage drum 1 of the thread delivery device F according to FIG. 6 serve the sliding drives 10 "and 11" for axial displacement one concentric to the axis of the storage drum 1 Ring element 27, the elastic with a sliding end 28 deformable middle section 8b 'of the thread braking element 8' (here a bristle ring) radially inside the support ring 9 acted upon directly. The support ring 9 is stationary in the holding member 7 fixed, for example by means of a Easily removable circlip 26. The two sliding drives 10 '' and 11 '' are combined, i.e. the Piston 10a '' in the sliding guide 12 'engages the ring element 27 by means of a piston rod 29, which at 30 with the Ring element 27 can be coupled while the return spring 19 'is arranged on the piston rod 29 and against one Stop at the end of the sliding guide 12 'works. Means of the piston 10a ″ is the ring element 27 in FIG shifted to the right up to a stop in the holding member 7, once the piston 10a '' from the pneumatic, not shown Drive control is pressurized with compressed air. As soon as the admission pressure is released, the Return spring 19 'the piston 10a' 'back, over the Piston rod 29, the ring member 27 also withdrawn is, expediently against a second stop of the holding member 7. In the position shown in Fig. 6 is the controllable outlet brake OYB disengaged, i.e. the brake active Inner area 8a 'is only essentially weak or no longer at all on the braking surface 4 'of the trigger edge 4 on. The middle section 8b 'is axial relative to the support ring 9 deformed.

As soon as the compressed air supply is reduced, the Return spring 19 'the ring body 27 back until the brake active Inner area 8a 'with the by the position of the carriage 22 preselected force is applied to the braking surface 4 '. The Return spring 19 'could also be on the right side of the ring element 27 are arranged so that the piston 10a '' directly attacks on the ring member 27. It could also be for both Movement directions of pneumatically actuated pistons as in Fig. 1 can be used. It would also be the other way round of the piston 10a '' and the return spring 19 'possible. Instead of the thread braking element 8 'with the bristles could a Flexbrake brake element 8 according to FIGS. 1 and 2 or a Toothed ring or a lamellar ring can be used.

In the schematically illustrated embodiment according to FIG. 7 forms the support ring 9 in the holding member 7 at the same time Piston K of the pneumatic sliding drive 10 '. The return spring 19 is either as in FIGS. 3 to 6 in one Sliding drive body 14 of the sliding drive 11 'for the other Direction of movement housed, or - as shown - in a recess of the support ring 9 so that a tab-like Projection 33, about an axis 34 in the holding member 7 to the side is pivotable, can be used. The support ring 9 is directly from the pneumatic drive control 12 with compressed air pressurized, possibly over several distributed inlets. The first investment area is inside one Annular chamber 32 of the holding member 7. The annular chamber 32 forms internal and external sealing areas 35 with the support ring 9. If necessary, a kind of piston ring seal is provided, which are also provided for the pistons 10a, 11a and 10a ″ and 10a ′ could be to keep compressed air leakage low and a consistently low displacement resistance of the respective Ensure piston. 7 is again a Bristle brake ring shown as the thread brake element 8 '. The individual bristles are labeled Q, those with their inner sides the brake-active interior area and thus a Define counter braking surface L. However, it could also be a Flexbrake thread brake element 8 or a toothed ring or a disk ring be used for the same purpose.

In the embodiment according to FIG. 8, there are several on the support ring 9 cylindrical projections distributed over the circumference as Piston 10a '' 'attached, preferably molded in one piece, inserted into sliding guides 12 'of the holding member 7 and be pressurized with compressed air. They form the Sliding drives responsible for one direction of movement 10 ', with even intervals over the circumference of the holding member 7 are distributed. The one for the other direction of movement responsible slide drives 11 'are for example as shown in FIGS. 3 to 5 and with return springs 19 provided, so that a detailed explanation is unnecessary. The thread brake element 8 is a Flexbrake thread brake element 1 and 2 with an annular or frustoconical Membrane M made of rubber or an elastic Elastomer containing at least one circumferential corrugation W, which have their elasticity and suspension properties in radial and axial direction increased. Inside the inside of the Corrugation W lying middle section 8b of the membrane M. on the inside a circumferential brake pad H with a truncated cone shape attached, e.g. glued, the counter braking surface L for defines the braking surface 4 'of the trigger edge 4. The brake pad H consists of a thread friction resistant Material, e.g. stainless steel or a copper-beryllium alloy and is relatively stiff in the axial direction, however in the radial direction, however, remarkably elastic. Also in this embodiment, instead of the thread braking element 8 another thread braking element can be used.

In Fig. 9, a projectile weaving machine MP is schematic and indicated with only one thread delivery device F. The thread delivery device F is aimed at the shed S and in Distance from it fixed. The thread Y comes from one not shown supply spool and is on the storage drum the thread delivery device in sufficient quantity cached and by the controlled outlet brake OYB deducted in the holding member 7. In the thread path from the thread delivery device in the shed S can a stationary thread eyelet be provided, behind which there is a controlled thread brake B is located. Between the controlled thread brake B and one Drive device A for one across the shed The projectile P to be fired is dependent on the web cycle controlled recording device T with at least one relative movable up and down to fixed thread guide points, arm grasping thread Y The drive device A in The opposite entry direction is at the other end of the shed S a safety gear G is provided for the projectile. The controlled thread brake B is controlled by a control unit CP the projectile weaving machine MP controlled and possessed depending on the web cycle possibly its own control unit C, the one Drive D controls. The control unit CP and / or the controller C is via line 40 to the pneumatic drive control 12 connected to the outlet brake OYB, such that the outlet brake OYB is roughly synchronized with the controlled one Thread brake is opened or closed. Alternatively the pneumatic drive control 12 (the solenoid valve the drive control 12) via its own control line 39 be connected to a sensor 38 which is connected to the one with the Main shaft 36 of the MP projectile loom rotatable encoder 37 is aligned to depending on the angle of rotation of the Main shaft 36 the commands to release or engage and also tap the times over which the OYB run-out brake loosened or indented.

When the projectile weaving machine MP is in operation, the drive device A thread Y held ready at first Pass projectile P and then through projectile P. shot the shed S before the projectile P with it connected thread Y is caught in the catching device G. Immediately before the entry begins, the controlled one Thread brake B released and also the controlled outlet brake OYB on the thread delivery device F. Towards the end of the flight of the The controlled thread brake B is engaged and projectile the controlled outlet brake OYB is also approximately synchronous. The controlled outlet brake OYB expediently becomes something prematurely indented to relax or sag Y thread between the controlled thread brake and the thread delivery device F to prevent or balloon formation suppress. It is important that the controlled outlet brake OYB is indented quickly so that it can be one hand for the thread control works correctly, but on the other hand one Excludes projectile flight delay.

11 illustrates the procedure for an entry. On the The horizontal axis of the graph is the angle of rotation for one Revolution of the main shaft 36 of the projectile weaving machine MP, while the vertical axis the thread tension (cN) or represents the switching voltage (V) for the solenoid valve. The curve 42 symbolizes the course of the thread tension, while curve 46 releasing and engaging and represents the sections of the angle of rotation over which the Outlet brake is engaged or released. At an angle of rotation the weft insertion begins at, for example, 110 °. The thread tension rises to a certain level once the projectile P accelerates and then runs approximately uniformly, up in a curve area 43 due to the controlled thread brake B the thread tension level first increases and then drops when the projectile P comes to a standstill and returns. At Projectile weaving machines MP would appear due to the immense acceleration of the projectile at the start of entry and due to a uncontrolled braking device at or downstream of the thread delivery device F a dreaded stroke of stretch that represented by the voltage peak 44 indicated by dashed lines is. However, since the controlled outlet brake OYB some Degrees of angle before the start of the entry (indicated at 47) is solved, and the thread delivery device extremely close can be placed on the controlled thread brake (which space saves), the stretching stroke 44 can be largely minimized or avoid completely, so that a harmonious curve arises in area 45. The controlled outlet brake OYB remains solved until near the end of the entry and is (at 48 indicated) only shortly before engaging the controlled thread brake B indented. It then remains until the end of the Entry indented to the thread between the thread delivery device and the controlled thread brake to exactly to control predetermined ways. Independent of the OYB outlet brake is engaged or released, it guides permanently a balloon limiter or balloon breaker function out.

In Fig. 10 is a rapier weaving machine MR with only a thread delivery device F shown. As an entry device serve a bringer gripper he BG and a slave gripper NG, which has a drive device 41 and a central Control unit CP are motion-controlled, such that they the Thread Y from one side of the shed S to the other side of the shed. The bringer gripper BG hands over the Thread in a transfer area Ü to the gripper NG, the the thread is completely transported through the shed S. The Control unit CP is expedient with the pneumatic Drive control 12 of the controllable outlet brake OYB in Holding member 7 of the thread delivery device connected to the controlled Runout brake OYB closed several times during each entry loosen or indent.

In the diagram of Fig. 12 is again on the horizontal axis the rotation of the main shaft of the rapier weaving machine MR applied from 0 ° to 360 °. The vertical axis represents the thread tension (cN) or the switching tension (V) for the solenoid valve of the pneumatic drive control 12. It there is an approximately heart-shaped curve 49 for the course the thread tension via a weft insertion. In the summit areas 51 the thread tension increases due to the acceleration the gripper on. The curve section is created in the transfer area 50 with low thread tension level. Usually is an uncontrolled thread brake on the thread delivery device and possibly even downstream of the thread delivery device at least one multi-disc brake with a fixed setting intended. This would result in the stretch stroke represented by the dashed voltage rise 44 is. However, since the controlled outlet brake OYB shortly before the start of the entry (represented by 53) is resolved, none Multi-disc brake is required, and the thread delivery device can be arranged very close to the shed (space saving), the stretching stroke 44 can be considerably minimized or completely eliminate them. The outlet brake OYB may only be solved immediately before the start of the thread Y not to leave yourself alone or relax beforehand allow. In the transfer area Ü from the grabber to the Slave gripper is required for a perfect thread transfer, to build a certain tension. To this Purpose is (represented at 54 of curve 52 of the switching signal for the pneumatic drive control) the controlled Outlet brake OYB engaged and during the transfer phase quickly after the handover phase (represented by 55) before it represents (before the end of the entry process by 56). It follows from this a precisely controlled thread control and one for sensitive thread material gentle thread tension profile, which enables the possible in modern rapier weaving machines high thread speeds without risk of thread breakage to use. The rapier weaving machine MR comes without arranged permanently downstream of the thread delivery device F. acting brakes that negatively affect the voltage curve would (stretch stroke and high peak areas 51).

In practice, the solenoid valve of the pneumatic drive control 12 housed inside the motor housing 3 protected and the supply lines are hidden. The solenoid valve leaves the one that is fed to act on the pistons Flow off compressed air directly when switching, namely expediently inside the motor housing to this through an overpressure effect or a dynamic flow Prevent contamination and lint from entering. It is even a targeted compressed air routing possible to critical Areas (the electronic components) in the motor housing or the sensor devices usually provided to keep clean or to clean or to cool in general. Usually all pneumatically operated sliding drives are sufficient jointly supplying or relieving solenoid valve out. However, it is also conceivable for everyone to be actuated pneumatically To assign a sliding solenoid to its own solenoid valve, to build up the necessary pressure quickly and the under Let the pressure of the air escape quickly. The pistons, the holding member 7 and any sliding guides of the sliding drives can be made of metal. The support ring 9 the thread braking element is expediently a plastic part, which is shaped in such a way that it is dimensionally stable at the lowest mass is. The braking surface 4 'is either in the range Trigger edge 4 of the storage drum arranged, or at the so-called front cone or nose part of the storage drum. In the first case, the braking surface and the counter braking surface work on a diameter of the storage drum together, which is slightly smaller than the diameter on which the thread turns 2a - 2n are. In the second case it is Diameter on which the braking surface with the counter braking surface works together, smaller than in the first case. The controller in the controllable outlet brake OYB depending on the course of the entry preference is given. But it is also conceivable control by means of a microprocessor, anyway in the control unit of the thread delivery device is in place to provide a program with exact for this purpose Predeterminable chronological sequence of triggering and engagement the outlet brake with every entry.

Claims (14)

1. A controllable output brake in a thread feed device (F) for projectile or gripper weaving machines (MP, MG), comprising a stationary storage drum (1) which has the thread (Y) supplied thereto and stored thereon in windings and from which said thread is drawn off discontinuously and overhead into the shed (S), said output brake (OYB) including an elastically deformable thread brake element (8), which is adapted to be pressed against a rotationally symmetric brake surface provided on said storage drum (1) and which is provided with an outer supporting ring (9), said supporting ring (9) being closed in the circumferential direction and arranged in a holding member (7) encompassing the storage drum (1) in a contact-free manner, and a displacement drive which is arranged in the holding member (7) and is adapted to be controlled by means of a drive control unit (12) when the thread feed device (F) and the weaving machine (MP, MG) are in operation, said displacement drive acting on the supporting ring (9) and being used for varying the force with which the thread brake element (8) is pressed against the brake surface (4), characterized in that the supporting ring (9) of the thread brake element (8) is adapted to be moved in said holding member (7) in the axial direction of the storage drum (1) with a predetermined amount of axial play relative to the brake surface (4) in two opposite directions, and that at least one push drive (10, 11, 10', 11') is provided as a displacement drive for each of said directions of movement of the supporting ring (9), said push drive being connected to the holding member (7) and operating exclusively parallel to the axis of said storage drum (1) and acting directly on said supporting ring (9), and said supporting ring (9) being adapted to be positioned by means of said push drive on a holding-member contact area (20, 21) located opposite thereto in the respective direction of movement.
2. A controllable output brake in a thread feed device (F) for projectile or gripper weaving machines (MP, MG), comprising a stationary storage drum (1) which has the thread (Y) supplied thereto and stored thereon in windings and from which said thread is drawn off discontinuously and overhead into the shed (S), said output brake (OYB) including an elastically deformable thread brake element (8'), which is adapted to be pressed against a rotationally symmetric brake surface provided on said storage drum (1) and which is provided with an outer supporting ring (9), said supporting ring (9) being closed in the circumferential direction and arranged in a holding member (7) encompassing the storage drum (1) in a contact-free manner, and a displacement drive which is arranged in the holding member (7) and is adapted to be controlled by means of a drive control unit (12) when the thread feed device (F) and the weaving machine (MP, MG) are in operation, said displacement drive being used for varying the force with which the thread brake element (8) is pressed against the brake surface (4), characterized in that the supporting ring (9) of the thread brake element (8') is supported in the holding member (7) in an immovable manner, said thread brake element (8') being provided with a central portion (8b') that is deformable relative to the brake surface (4') axially and elastically in two opposite directions, that at least one push drive (10'', 11'') is provided as a displacement drive on the holding member (7) for each of said axial deformation directions of said central portion (8b'), said push drive operating parallel to the axis of the storage drum (1) and acting directly on said deformable central portion (8b'), that a ring element (27) which is concentric with the axis of the storage drum (1) is supported on said holding member (7) in an axially displaceable manner, said ring element having a pushing end (28) which is in alignment with the central portion (8b') and is adapted to be acted upon by said push drives (10'', 11'') so as to displace said ring element (27) between a release position defined by a stop of the holding member (7) and a passive position defined by a stop of said holding member (7), said central portion (8b') being, at said release position, elastically deformed by the pushing end (28) in the axial direction relative to the supporting ring (9), whereas, at said passive position, the pushing end (28) will at most abut approximately weakly on said central portion (8b').
3. A controllable output brake according to claim 1, characterized in that the drive control unit (12) is a pneumatic unit.
4. A controllable output brake according to claim 3, characterized in that at least the push drive (10, 11, 10') connected to the pneumatic drive control unit (12) for one direction of movement is a piston (10a, 11a, 10a') which is arranged in a slide guide means (12, 13) of the holding member (7) and which directly acts on the supporting ring (9), and that the push drive (11') which is not adapted to be pneumatically acted upon includes at least one permanently active, biased restoring spring (19) which is preferably contained in a sleeve (18).
5. A controllable output brake according to claim 3, characterized in that two pistons (10a, 11a) acting in opposite directions are provided, and that the two pistons are adapted to be acted upon alternately by the pneumatic drive control unit (12).
6. A controllable output brake according to claim 3, characterized in that two pistons (10a, 11a) acting in opposite directions are provided in the two push drives (10, 11), the pressure area of one of said pistons (11a) being larger than the pressure area of the other piston (10a), and that the piston (10a) is adapted to be pneumatically acted upon permanently, whereas the piston (11a) is pneumatically acted upon only in cycles.
7. A controllable output brake according to claim 3, characterized in that the supporting ring (9) is implemented as a piston (K) of the push drive (10'), which is adapted to be directly acted upon by the pneumatic drive control unit (12) in the holding member (7) and for which said holding member (7) defines a slide guide means (35).
8. A controllable output brake according to claim 3, characterized in that the supporting ring (9) has arranged thereon pistonlike projections (10a'''), which are preferably formed integrally with said supporting ring (9) and which engage slide guide means (12') provided in said holding member (7), said pistonlike projections (10a''') being adapted to be pneumatically acted upon in said slide guide means (12').
9. A controllable output brake according to claim 3, characterized in that the holding member (7) has provided there-on the contact areas (20, 21) in parallel and in an approximately annular shape, said contact areas (20, 21) being in alignment with the supporting ring (9) and being arranged at an axial distance from one another that is larger than the axial width of the supporting ring (9).
10. A controllable output brake according to at least one of the claims 1 and 3 to 9, characterized in that the holding member (7) is implemented such that it is open towards a removal side (E) of the thread brake element (8) and that it carries on said removal side (E) at least one push drive element (14) which is adapted to be moved to and fro between a removal position located outside of the removal path of the thread brake element (8) and a preferably self-holding hold position at which the push drive element (14) engages behind the supporting ring (9).
11. A controllable output brake according to claims 3 and 10, characterized in that the restoring spring (19) is extendably supported in the push drive element (14), and that the holding member (7) is provided with a restoring-spring supporting surface (17), which is preferably located in a recess (25) for the push drive element (14) moved to the removal position by a pivotal movement, said supporting surface (17) being arranged at a distance from the first contact area (20) which corresponds approximately to the axial width of the supporting ring (9).
12. A controllable output brake according to at least one of the claims 1 to 11, characterized in that the supporting ring (9) has supported thereon an annular diaphragm (M) consisting of rubber or of an elastomer and defining a central portion (8b), said diaphragm having formed therein at least one concentric, circumferentially extending resilient corrugation (W) and carrying in the area of its inner diameter a frusto-conical, circumferentially extending, wear-resistant brake lining (H) defining an uninterrupted counterbrake surface (L) of the thread brake element (8).
13. A projectile weaving machine (MP) comprising at least one thread feed device (F) with a controllable output brake (OYB) according to at least one of the claims 1 to 12, and a thread brake (B) controlled in dependence upon the weaving cycle as well as a take-up device (T) between the output brake (OYB) and the shed (S), characterized in that the pneumatic drive control unit (12) of the output brake (OYB) is connected to a control (C, CP) of the controlled thread brake (B) or of the weaving machine (MP) in such a way that, when the controlled thread brake (B) is being disengaged, the braking effect of the output brake (OYB) can be reduced approximately synchronously until the thread brake element (8, 8') abuts approximately weakly on the brake surface (4'), and, when the controlled thread brake (B) is being engaged, said braking effect can be increased approximately synchronously, preferably slightly in advance, until a maximum value has been reached, which can be predetermined by the basic axial adjustment of a holding-member carriage (22).
14. A gripper weaving machine (MG) comprising at least one thread feed device with a controllable output brake (OYB) according to at least one of the claims 1 to 12, and further comprising a presenter gripper (BG) and a receiver gripper (NG), which are adapted to be cooperatingly driven, characterized in that the pneumatic drive control unit (12) of the output brake (OYB) is connected to a control device (CP) for the grippers (BG, NG) by means of which the braking effect of the output brake (OYB) can be varied several times between a minimum and a maximum value in dependence upon the movements of said presenter gripper (BG) and said receiver gripper (NG) during each picking cycle.

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