EP0942892B1 - Yarn feeding device for a yarn tension device - Google Patents

Description

The invention relates to a thread delivery device according to claim 1 and claim 8 and a thread brake according to claim 15.

In a generic thread delivery device known from US-A-5 316 051 the brake band carrier, e.g. a Kevlar truncated cone coat, on the small-diameter End held on the outside by a circular membrane, which forms the spring arrangement. The circular membrane is defined in the support, which runs along a The boom of the thread delivery device can be adjusted and the axial pretensioning force for pressing the brake band onto the trigger edge on the brake band carrier transfers. Thread brakes shown schematically in US-A-5,316,051 are disclosed in US Pat Practice designed so that the circular membrane is arranged by several star-shaped Tension springs is replaced. This shows up gradually in use significant spread between the suspension properties or spring forces of the parallel tension springs, which worsens the centering effect. Kick it Bad positions of the brake band carrier relative to the storage body axis on and a non-uniform along the circumference of the trigger edge of the storage body Braking effect of the brake band. Of the tension springs is almost because of one 90 ° force deflection only a fraction of the spring action to generate the axial Preload force used, so that an extremely high axial force on the tension springs is to be brought up.

From WO95 / 00431 a thread delivery device is known in which the brake band of the Thread brake by means of a conical circular membrane made of rubber against the Deduction margin is pulled. The circular membrane is with its large diameter End fixed in a retaining ring, which extends over a cardan bearing supports two cardan axles in the support. The gimbal can an equilibrium position of the retaining ring centered on the storage body axis to ensure. However, since the spring arrangement is integrated in the circular membrane is, misalignment of the brake band to a along the circumference of the Uneven braking effect lead trigger edge. It can namely Do not form the annular membrane so homogeneously that it which together give the axial preload force, uniform in the circumferential direction transfers. Local aging influences can also influence such Increase inhomogeneities. As the circular membrane as a spiral spring and tension spring works, a noticeable part of the axial force introduced by internal Deformation work consumed, so that a relatively large axial force is required becomes.

In both known thread delivery devices, the thread brake builds with its spring arrangement and the support of the spring arrangement relatively extensive, which the Can hinder access to the storage body.

In a yarn delivery device known from DE-U-94 06 102 is for the brake band a truncated cone-shaped holding member is provided, which is axially and radially stiff, relatively thick-walled body is formed. This holding member is in the axial direction cushioned by a group of axial coil springs around the trigger eye are distributed concentrically and rest on a stationary support. The holding member remains essentially at rest in the operation of the thread delivery device. The brake band lies on a conical ring surface at the end of the storage drum on. So that the brake band yields elastically in the passage area of the thread can, is an elastic intermediate layer between the brake band and the holding member used in the form of a truncated cone foam ring.

Further prior art is contained in DE 44 07 958 A. As intermediate literature DE 195 42 045 A comes into question.

The invention has for its object a thread delivery device and a thread brake to create the type mentioned, with a compact structure the thread brake a perfect centering of the brake band on the storage body and achieve uniform braking conditions in the circumferential direction, and those in the power transmission from the support to the brake band as little force as possible is wasted.

The stated task is in each case with the features of claim 1, the Claim 8 or claim 15 solved.

The universal joint ensures thanks to its positioned in the storage body axis Joint center for an optimal, because positive locking centering of the brake band on the trigger margin, since there is no significant transverse elasticity, and leaves nevertheless, the brake band carrier tilts in all directions. This guarantees a constant braking effect for the thread in the circumferential direction between the brake band and the trigger edge. Even with one in relation uneven power transmission from the spring arrangement to the storage body axis the universal joint embraces everyone, so to speak the force components acting together in the joint center initially in the joint center and distributes the resulting total force uniformly from the center of the joint to the brake band. Since, according to the exemption from the spring arrangement of a centering task with the universal joint centered on the storage body axis can make a direct axial spring force transmission result there is little loss in power transmission. A relatively weak one is enough Spring arrangement with low support force for the necessary axial preload out. The universal joint and the spring arrangement can be opened Place a small amount of space or one behind the other in the thread pull-off direction switch so that access is hardly hindered. The masses of moving components can be very small, especially if the universal joint arranged between the brake band carrier and the support and by the spring arrangement is bypassed what the response of the thread brake is cheap. Because the universal joint is used for centering and the spring arrangement these two component groups can be exempt from this task optimally designed for their respective purpose, and can be Set the preload precisely and sensitively. The brake band carrier remains relative tilting movements and axial displacements are positively centered, and can even be rotated without affecting the centering become.

The thread brake (claim 15) can be an integral part of the thread delivery device be, but also an optional add-on unit for different thread delivery devices or thread delivery devices within the same series. The universal joint, in which the brake band carrier is axially adjustable and can tilt for a mechanical, because form-fitting centering without in the transverse direction noticeable spring component. The brake band carrier still keeps it for Working cycle required degree of freedom. Because tilting movements in the universal joint and axial displacements take place while maintaining the centering a small moving mass is realized and the resistance to movement remains low in the universal joint, which is a sensitive response of the thread brake results. The sensitive response has the advantage that the Thread brake even at very high thread speeds or high frequencies of thread tension changes and adapts to such thread brakes the desired self-compensation is largely unaffected, i.e. e.g. with thread speed or acceleration dependent thread tension increases automatically reduces the braking effect.

The separation of duties: form-fitting centering and transfer of the preload is useful (claim 2) if the universal joint between the Spring assembly and the brake band carrier instead of one by spring action certain, inaccurate centering effect a constant positive and axially movable centering of the brake band and the spring arrangement is only used to transmit the pressing force.

The universal joint can (claims 3, 4, 5) a universal joint or a ball joint his. Even with an axial shift, it is free and easy to move on all sides The mobility of the brake band carrier is ensured relative to the spring arrangement and finds the transmission of the pressing force from the spring arrangement to the Brake band instead of noticeable losses. A small all-rounder is sufficient Tilt range of motion. In all cases, the smooth tilt and Axial mobility of the brake band carrier ensured, even when the universal joint works in a small installation space (small effective diameter). The universal joint is guided axially on the support, so that eccentric forces Spring arrangement does not cause misalignment of the brake band carrier.

According to claim 6 is a clean guide of the thread through the support and reached the culvert. Any power components from the deflection of the thread in the pull-off eye are picked up and influenced in the universal joint the centering of the brake band carrier is not. It can be useful the brake band carrier must be attached to the trigger eye. The trigger eyelet may be a joint element of the universal joint. Training then results from a few individual parts. The support can only be a fraction of the Claim the diameter of the storage body. Nevertheless are optimal lever arms given when centering the brake band carrier.

With regard to the operational safety of the thread brake, it is (claim 7) expedient to shield the universal joint. In the operation of a thread delivery device lint and impurities originating from the thread material arise, which show the tendency to deposit disturbingly between moving components. This is avoided by the cover. The flexibility of the cover ensures that the mobility of the brake band carrier is not impaired. It is particularly useful (claim 13); the thread brake by means of the cover to ventilate the brake band carrier when applying vacuum the brake band lifts off the trigger edge or at least largely relieves it, so that threading a thread into the thread brake is facilitated. The pressurization the chamber can be a pneumatic threading system belong with which the thread automatically through the thread delivery device and threading the thread brake.

According to claim 9, there is a compact structure with few individual parts. When working, there are very small moving masses, since there is only one joint element moved with the brake band carrier. The spring arrangement acts the brake band carrier either directly or via the one holding the brake band carrier Joint element. The radial play can be so slight that the centering function is not noticeably impaired, but the, albeit limited, All-round tiltability of the brake band carrier C is guaranteed. It is one game-locking form-fitting connection of the joint elements, which actually works like a universal joint because of the radial play.

The brake band carrier can (claim 16) directly with its conical end section be held in the joint element. The brake band carrier is expedient only loosely caught in the seat, e.g. to avoid falling out during transport, because during operation the pre-tensioning force for positioning the brake band carrier on the joint element. One joint element can be concave thanks to its Curvature in the passage on the other joint element the required Carry out tilting movements and still remain centered. It would be too conceivable to design the passage approximately cylindrical and a spherical Provide surface on the other joint element.

According to claim 11, the brake band carrier is loosely inserted into the seat in which he remains positioned under the axial preload. That with an open one Seat formed a hinge element can be a one-piece, lightweight Plastic molding.

Alternatively, according to claim 12, the one joint element is composed of ring parts, which, for example, by a press fit or another type of Connection are fixed to each other and the seat for the brake band carrier limited between themselves. In the event that one joint element, for example is injected onto the brake band carrier, this joint element could even be formed in one piece. Two ring parts that limit the seat provide the Advantage, the brake band carrier with its brake band as a wearing part easily to be able to replace.

According to claim 13, the axial biasing force on the system and one Transfer the joint element to the brake band carrier.

According to claim 14, the one joint element is not directly on the stationary one Support centered, but on the other, in the sleeve body of the support fixed joint element.

The joint elements of the universal joint are expediently made of plastic, at least in their mutual contact areas. A self-lubricating Plastic can contribute to the lowest possible resistance to movement sure.

Fig. 1

einen schematischen Längsschnitt eines Teils eines Fadenliefergeräts mit einer Fadenbremse,

Fig. 2

einen Längsschnitt einer konkreten Ausführungsform,

Fig. 3

einen Radialschnitt in Fig. 2,

Fig. 4

einen Schnitt einer weiteren Ausführungsform, und

Fig. 5

einen Teillängsschnitt einer weiteren Ausführungsform einer Fadenbremse für ein Fadenliefergerät.

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

Fig. 1

1 shows a schematic longitudinal section of a part of a thread delivery device with a thread brake,

Fig. 2

2 shows a longitudinal section of a specific embodiment,

Fig. 3

3 shows a radial section in FIG. 2,

Fig. 4

a section of a further embodiment, and

Fig. 5

a partial longitudinal section of a further embodiment of a thread brake for a thread delivery device.

A drum-shaped storage body 1 of a thread delivery device F is shown in FIG a front trigger edge 2, a storage body axis X and a housing bracket 16 indicated on which a thread brake cooperating with the storage body 1 B, for example adjustable in the direction of a double arrow 15 is. The thread delivery device F with this thread brake B is used in particular for Delivery of weft threads in projectile or rapier weaving machines.

The thread brake B has a brake band A which is continuous in the circumferential direction the shape of a truncated cone, which in the large-diameter end region of a Brake band carrier C also attached with the shape of a truncated cone is and with axial biasing force and at least approximately to the axis X coaxial Alignment is pressed against the trigger edge 2. The trigger edge 2 runs in Circumferential direction is continuous and is in a longitudinal section of the storage body 1 rounded (line contact) or conical (surface contact). The brake band A exists made of wear-resistant material, preferably of metal or a metal alloy such as Beryllium copper, and has a strength easily deformable. The brake band carrier C is in Axial direction stiff, but at least in the region of its large diameter end radially easily deformable. It consists of e.g. transparent, plastic or fiber-reinforced plastic material and supports itself with its small diameter End area in a stationary support D, which by means of a holding part 13, e.g. is mounted on a carriage 14 in the boom 16.

A thread (not shown) is stored in turns on the storage body 1 and is pulled off overhead or over the trigger edge 2, inwards in the direction deflected to the axis X, and then enters a central trigger eye E, preferably made of ceramic material, before it passes through the support D in a duct 3 is withdrawn essentially axially. In the mutual contact area of the Brake band A and the trigger edge 2 is a closed in the circumferential direction Braking zone in which the thread is braked when pulling off.

The support D has a housing 9, the outer diameter of which may be considerable can be smaller than the outer diameter of the storage body 1. In the housing 9 is a sleeve part defining a cylindrical guide surface parallel to the axis X. 4 arranged, the abutment 5 for a spring arrangement S (in the present Case has a cylindrical helical compression spring 6). On the sleeve part 4 is parallel to the axis X, a sleeve 7 guided telescopically, which acted upon by the compression spring 6 Has flange 8.

In the support D is a universal joint U as a ball joint K with one in the Axis X lying joint center Z is provided, which consists of at least two joint elements U1 and U2 exist. The sleeve 7 defines the first joint element U1 a front bearing surface 12 (e.g. a ball socket that is continuous in the circumferential direction or consists of individual sections). The second joint element U2 is formed in the embodiment shown by the trigger eyelet E, which at their has a counter bearing surface 11 (e.g. a spherical spherical surface that runs continuously in the circumferential direction or from individual Sections exists). The sphere radius is indicated by r. The joint center Z lies on the X axis, for example, between the trigger eye E and the front of the storage body 1. In the ball joint K, only the bearing surface could 12 or the counter bearing surface 11 may be spherical around the center of the joint To define Z. The other surface could only be essentially punctiform adjacent crests or surfaces are formed.

The brake band carrier C fastened to the trigger eye E in this embodiment is inserted into a seat 10 of the trigger eye E and, if necessary, fixed, e.g. by gluing or the like. It could also only be used loosely (rotatable) because it is anyway is held positioned by the axial preload.

In Fig. 1, the axial biasing force for pressing the brake band A to the Trigger margin 2, e.g. adjusted by the axial position of the support D and resilient from the spring arrangement S to the first joint element centered on the axis X. U1 transmitted. The brake band carrier C is in the universal joint U on the axis X centered. The biasing force is transmitted from the bearing surface 12 to the bearing surface 11 and focused on the hinge center Z, and then on all sides evenly introduced into the brake band carrier C, the brake band A in the circumferential direction presses uniformly against the trigger edge 2.

In Fig. 2, the universal joint U is inside the support D as a universal joint H formed with first, second and third joint elements U1, U2 and U3, wherein the first joint element U1 is formed by the sleeve 7 analogously to FIG. 1, which on the sleeve part 4 is guided parallel to the axis X and by the compression spring 6 of the spring arrangement S is acted upon axially. The sleeve 7 defines an inner ring that over a first cardan shaft 18 (Fig. 3) from two stub axles with a third joint element U3 defining intermediate ring 26 is coupled such that the intermediate ring 26 is pivotable about the first cardan shaft 18. The intermediate ring 26 is Via a second cardan shaft 17 from two stub axles with one the second joint element U2 forming outer ring 25, which in turn is coupled to the outside of the brake band carrier C is connected. The cardan axes 17, 18 are approximately perpendicular to each other and cross the axis X, so that the hinge center Z in the Axis X is defined, around which the brake band carrier C relative to all sides Support D is pivotable. This is an internal thread in this embodiment having spring abutment 5 'is in the support D on the with an external thread provided sleeve part 4 and can be rotated by rotating the sleeve part 4 (via a rotary knob, not shown, which engages on the projection 24) in Adjust the axial direction to - if desired - the preload force of the spring arrangement S to be able to change. For this, e.g. the spring abutment 5 'rotatable and axially adjustable in the support D out. Additionally or alternatively, if desired, the support D can be adjusted in the axial direction similar to that in FIG. 1.

The universal joint U is shielded from the outside by a wall 23, which as flexible membrane formed and in the housing 20 of the support D and on the outer ring 25 is set. A chamber 21 is provided in the housing 20 behind the wall 23, which can be connected to a vacuum source 22 (indicated schematically), to counter the universal joint U and the brake band carrier C by means of the wall 23 the biasing force of the spring assembly S (to the right in Fig. 2) to move and to lift the brake band A from the trigger edge 2 or at least opposite the Relieve trigger edge 2.

The brake band carrier C is formed with a tubular extension 19, which in the trigger channel 3 engages with radial play. The one specified in the brake band carrier C. Draw-off eyelet E serves to deflect the drawn-off thread into the draw-off channel 3. The tubular extension 19 could (as in FIG. 1) also be molded onto the trigger eyelet E. his. The function of this embodiment corresponds to that of FIG. 1.

Analogously to the embodiment according to FIG. 1, the trigger eyelet E or a part holding this can be designed as a hinge element U2 by the number of parts to decrease. Furthermore, it would be conceivable, in Fig. 2, the universal joint H inside to be arranged in the sleeve 7 and thus on a smaller effective diameter. In Fig. 1 the ball joint K as the universal joint U could also be designed such that the ball socket is provided in the second joint element U2 and the front end of the Sleeve 7 overlaps outside, instead of intervening there from the inside.

In Fig. 2 the joint center Z is approximately in the imaginary cone tip of the brake band carrier Z. The power transmission zone between the spring assembly S and the Sleeve 7 is approximately the same distance from the axis X as the connection area between the outer ring 25 and the brake band carrier C. It grips from the deflection forces of the thread in the take-off eye E with respect to the axis X further on than the force components of the spring arrangement S on the sleeve 7 or in the universal joint U. The outer diameter of the support D can be increased by 20 to 70% smaller than the outside diameter of the storage body 1. The cone tip angle the brake band carrier or the brake band A can, depending on the application the thread brake or the thread delivery device F may be different. The cover of the universal joint U with a wall 23 analogous to FIG. 2 can also be used 5 or 5 may be provided.

4 is the axially displaceable universal joint U formed by a rolling bearing W, the bearing rings 27, 28 spherically curved Have rolling surfaces so that the bearing ring 29 by means of the rolling elements 28th All-round tilting movements around the center of the joint Z can perform. The bearing rings 27, 29 and the rolling elements 28 form joint elements U1, U2, U3 of the universal joint. The rolling elements can be balls, barrels or rollers, the Tons should have curved surfaces. The outer bearing ring 29 is in the Set sleeve 7, which is acted upon by the compression spring 6 and guided axially. The inner bearing ring 27 holds the trigger eyelet E, at whose seat 10 the brake band carrier C is set. The rolling bearing could alternatively also be arranged on the outside of the sleeve 7 his. Furthermore, analogously to FIG. 2, the brake band carrier could directly or through mediation an intermediate part to be connected to one of the bearing rings and the trigger eye E record.

In all the embodiments shown, in particular in the embodiment according to Fig. 4, if necessary, the brake band carrier C with the brake band A smoothly in the support D and relative to the trigger edge 2 about the storage body axis X twist, in the seat 10 and / or in the universal joint U.

In Fig. 5 is a thread brake B in longitudinal section without an associated thread delivery device shown, the universal joint U consists of two joint elements U1 and U2, and in which the brake band carrier C by the compression spring 6 of the spring arrangement S on the one joint element U2 or (not shown) directly with the axial biasing force is applied. The compression spring 6 is supported on the spring abutment 5 ', which in the stationary support D is non-rotatable, but axially displaceable and is supported by the sleeve part 4 of the support D which is stationary in the axial direction. The Sleeve part 4, in which the discharge channel 3 runs, can be by means of the right-hand side Turn the rotary knob to the preload of the compression spring 6 by means of the then to change axially moving spring abutment 5 '.

The other joint element U1 is, for example, a sleeve body 30, e.g. out Plastic, which is inserted into the sleeve element 4 with a securing end 32 and can be committed to this. The sleeve body 30 has at least one Part of its longitudinal extent a cylindrical outer circumference 31, which with the a joint element U2 cooperates in the universal joint U In the sleeve body 30 is the Pipe extension 19 'held, the stationary withdrawal eye E in a funnel-shaped Expansion 33 contains. A thread drawn from the storage body, not shown Y runs through the braking zone at a distance from the inner wall of the brake band carrier C up to the trigger eye E, without the components of the universal joint to touch. The thread Y is then conveyed further through the draw-off channel 3.

One joint element U2 consists of two in the embodiment shown Ring parts 34 and 40, which limit the seat 10 for the small-diameter, conical ends 45 of the brake band carrier C are connected to one another, e.g. by a press fit, by gluing or screwing or in the manner of a bayonet lock. The ring part 34 has an internal passage 35 with an inner wall 36, whose generatrix (with respect to the axis X) is convexly curved. The Inner wall 36 includes the cylindrical outer periphery 31 of the other joint element U1 with a possibly only slight radial play 50, i.e. in one light sliding seat. The convex curvature of the inner surface 36 can be geometrical be designed so that the one hinge element U2 on all sides tilt (at least in a limited range of motion) and axially on the other Joint element U1 can be moved, and if necessary also rotated smoothly is. Thanks to the radial play 50, the center device of the brake band carrier can be C structurally simple to the effect of the universal joint U to receive. The center of articulation Z can be roughly in the axis X (or the extension the axis X of the storage body).

The outer edge region of the ring element 34 has a circumferential flange 37, which forms a boundary 38 for the seat 10. On a roughly cylindrical approach 39 of the ring part 34, the other ring part 40 is applied, with its outer edge region defines a further limit 41 for the seat 10 and, moreover, for example at 43, can be fixed in a press fit. The back of the other Ring part 40 forms a stop 42 for the compression spring 6. One ring part 34 reaches through the other ring part 40. The inner surface 36 rises in FIG. 5 rounded on the left and also to the right. At least the contact surfaces of both Joint elements U1, U2 can consist of plastic, expediently of self-lubricating plastic. If necessary, both joint elements U1, U2 made of plastic, expediently as plastic injection molded parts.

In Fig. 5 it is indicated by dashed lines at 44 that the seat 10 of the one joint element U2 could be open to the left, i.e. that the peripheral flange 37 of the Ring part 34 is omitted. Just by the axial preload and the reaction force from the storage body namely the brake band carrier C in the then open Seat 10 positioned. For the rest, it is appropriate to the seat 10, even if it is limited on both sides by the limits 38 and 41 so that the small-diameter conical end region 45 of the brake band carrier C is only held loosely is so that its radial flexibility is not due to a fixed clamping in the seat 10 is noticeably impaired. It is also conceivable that the one joint part U2 in one Inject the injection mold directly onto the brake band carrier C in one piece.

A reverse design of the universal joint U shown in FIG. 5 can also be used provide, i.e. that the passage 35 could be approximately cylindrical, on the other hand, a spherical outer bead is provided on the other joint element U1 becomes. Finally, it is possible to ring the ring 34 with individual in the circumferential direction distributed fingers with spacing, the inside of the passage 35 or define the inner wall 36. This would allow the mass of one Reduce joint element U2 further. Since the universal joint U in Fig. 5 for the Tilting and sliding function using the radial play 50, the centering could round surfaces 31, 36 may even both be cylindrical. It could also be the passage 35 even have a cutting-like inner ring edge.

Claims (15)

1. Yarn feeding device (F) including a yarn brake (B) comprising a thin, wear-proof, circumferentially continuous, radially deformable braking band (A) of frustocone jacket shape situated in a large diameter end section of a braking band carrier (C), said braking band arranged substantially coaxially to the axis (X) of a storage body (1) of the yarn feeding device (F) and held with its inner side at a frontal, circumferentially continuous withdrawal rim (2) of said storage body (1), further including a stationary support (D) for a spring assembly (S) imparting an essentially axial pre-loading force to said braking band carrier (C), said braking band carrier (C) having the shape of a frustocone jacket and being axially stiff but radially deformable, characterised in that a universal joint (U) is provided between said spring assembly (S) and said braking band carrier (C), said universal joint comprising at least two mechanically and positively co-operating joint elements (U1, U2, U3) with the joint centre (2) of the universal joint (U) positioned substantially in the prolongation of the axis (X) of the storage body (1).
2. Yarn feeding device as in claim 1, characterised in that the universal joint (U) forms a centring device for braking band carrier (C) connected therewith, said centring device, axially actuated by said spring assembly (S), being axially displaceable within said support (D).
3. Yarn feeding device as in claim 1, characterised in that said universal joint (U) is a Cardanic joint (H) having two Cardanic axes (17, 18) substantially perpendicular to each other and intersecting the storage body axis (X), and that said Cardanic joint (H) comprises an inner ring centred in the support (D) and having bearing facilities for the first Cardanic axis (18), an intermediate ring (26) pivotable about the first Cardanic axis (18) and having bearing facilities for the second Cardanic axis (17), and an outer ring (25) pivotable about the second Cardanic axis (18) and connected to the braking band carrier (C).
4. Yarn feeding device as in claim 1, characterised in that said universal joint (U) is a ball joint (K).
5. Yarn feeding device as in claim 4, characterised in that said ball joint (K) comprises a bearing surface (12) centred in said support (D) and a joint element (U2) with a counter bearing surface (11), said joint element (U2) being supported for movements about the joint centre (Z), and that at least said bearing surface (12) or said counter bearing surface (11) is formed as a spherical socket of the ball joint.
6. Yarn feeding device as in claim 1, characterised in that in the small diameter end section of the braking band carrier (C), a withdrawal eyelet (E) is provided which defines said one joint element (U2) of the universal joint (U), and that, preferably, said braking band carrier (C) is fixed to said withdrawal eyelet (E).
7. Yarn feeding device as in at least one of the preceding claims, characterised in that said universal joint (U) is arranged in the interior of said support (D) and is shielded outwardly by a flexible shielding (23) being a moveable wall of a chamber (21) of the support (D), said wall being connected to the universal joint (U), and that said chamber (21) is connectable to a low pressure source (22) to lift said braking band (A) from said withdrawal rim (2) via said universal joint (U).
8. Yarn feeding device (F) including a yarn brake (B) comprising a thin, wear-proof, frustocone jacket shaped, radially deformable, circumferentially continuous, braking band (A) being in a large diameter end section of a braking band carrier (C), said braking band arranged substantially coaxially to the axis (X) of a storage body (1) of the yarn feeding device (F) and held with its inner side at a frontal, circumferentially continuous withdrawal rim (2) of the storage body (1), further comprising a stationary support (D) for a spring assembly (S) imparting an essentially axial pre-loading force to said braking band carrier, said braking band carrier (C) having the shape of a frustocone jacket and being axially stiff but radially deformable, characterised in that the braking band carrier (C) at the stationary support (D) is positively centred in a universal joint (U) about said axis (X), said universal joint (U) allowing said braking band carrier displacements in the direction of axis (X) and tilting motions to all sides.
9. Yarn feeding device as in claim 8, characterised in that that the universal joint (U) has two joint elements (U1, U2) positively co-operating with a radial clearance (50), that one joint element (U2) is holding said braking band carrier (C) while the other joint element (U1) is connected to the stationary support (D), that said one joint element (U2) is moveable relative to the other substantially in the direction of axis (X) and is tiltable to all sides and optionally rotatable, and that said spring assembly (S) loads said braking band carrier (C) directly or via said one joint element (U2).
10. Yarn feeding device as in claim 8, characterised in that the braking band carrier (C) engages by its small diameter end section into a seat (10) formed in said one joint element (U2), preferably by means of a conical end section (45) and in a substantially loose manner, that said one joint element (U2) is formed inside of said seat (10) with an essentially funnel-shaped passage (35) having an inner wall (36), the generatrice of which - at least in the region of the smallest inner diameter and seen in a longitudinal section - is curved convexly, and that said other joint element (U1) has an essentially cylindrical guiding periphery (31) on which said inner wall (36) is arranged in a sliding fit, optionally with said small radial clearance (50).
11. Yarn feeding device as in claim 10, characterised in that said seat (10) is formed open in a direction towards said braking band carrier (C), and that, preferably, said one joint element (U2) is formed as a unitary structure with said seat (10) and said passage (35).
12. Yarn feeding device as in claim 10, characterised in that said one joint element (U2) consists of two mutually engaging ring parts (34, 40) defining said seat (10) between them.
13. Yarn feeding device as in claim 12, characterised in that one of said ring parts (34) has the passage (35) and a limitation (38) of said seat (10), and that the other ring part (40) surrounds said one ring part (34) and forms a further limitation (41) of said seat (10) as well as a stop (42) for said spring assembly (S, 6), said stop (42) facing away from said seat (10).
14. Yarn feeding device as in claim 8, characterised in that the stationary support (D) includes a sleeve body (4) extending towards said universal joint (U), and that the other joint element (U1) is inserted into axial abutment into said sleeve body (4).
15. Yarn brake (B) for a yarn feeding device (F), having an axially stiff but radially flexible braking band carrier (C) with the shape of a frustocone jacket said braking band carrier holding in its large diameter end section a thin, wear-proof, circumferentially continuous, radially deformable, frustocone jacket shaped braking band (A) substantially coaxial to an axis (X) of said yarn brake (B), and further having a stationary support (D) for a spring assembly (S) imparting an essential axial pre-loading force on to said braking band carrier (C), characterised in that by a universal joint (U) said braking band carrier (C) is positively centred at said stationary support (D) about said axis (X) and is displaceable in the direction of and tiltable to all sides of said axis (X).

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