EP2623650A1

EP2623650A1 - Yarn feeder and yarn brake

Info

Publication number: EP2623650A1
Application number: EP13000411.2A
Authority: EP
Inventors: Thomas Bergman
Original assignee: Iro AB
Current assignee: Iro AB
Priority date: 2012-02-02
Filing date: 2013-01-28
Publication date: 2013-08-07
Anticipated expiration: 2033-01-28
Also published as: EP2623650B1; CN103243460A; CN103243460B

Abstract

A yarn feeder (F), comprising a storage body (4) with a withdrawal rim (4b), a yarn brake (B) including a hollow frusto-cone body (9), deformable in radial direction but essentially stiff in axial direction and resiliently forced against the withdrawal rim (4b) coaxially with an axis (X) of the storage body (4), and a substantially annular oscillation damper (14) associated with the frusto-cone body (9) as a counter-mass damper suppressing oscillations of the frusto-cone body (9), and a yarn brake (B) for yarn feeders (F).

Description

The invention relates to a yarn feeder defined in the preamble part of claim 1 and to a yarn brake defined in the preamble part of claim 9.
Various variants exist of such yarn brakes for yarn feeders, one of which is disclosed in EP 2 213 776 A1 . The frusto-cone body of the known yarn brake consists of a high-performance thermoplastic polymer such as polyketone. The known yarn brake is a structural unit and may be incorporated into a yarn feeder. The known yarn brake has since its introduction in the textile field proven excellent performance, e.g. in view of wear resistance and good yarn tensioning properties. However, experiences in the textile field recently indicated that for specific types of yarns, namely coarser and/or stiffer yarns, like coarse cotton yarns, chenille or similar difficult or delicate yarns, a further improvement of the yarn brake would yet be desirable in order to achieve an optimum performance of the yarn brake.
It would be important to assure essentially the same yarn tension profile (tension curve) from one working cycle to the next in the textile machine. For example, in the case of a rapier or projectile weaving machine an essentially identical yarn tension profile should be achieved from one weft insertion (so-called pick) to the next, and on a continual basis. In the case of a knitting machine, however, where the yarn in most cases, is not inserted intermittently as in a weaving machine, but more or less continuously fed into a knitting system, it would be important to assure a stable, constant yarn tension level on a continual basis (constant and uniform over time).
The braking performance of such yarn brakes may namely be somewhat deteriorated in processing the above-mentioned delicate yarns by unavoidable resonance oscillations, also called "natural or self-oscillations" of the frusto-cone body. Such oscillations occur when the yarn withdrawn from the storage body of the feeder through the braking nip and while orbiting generates a crescent-shaped, circumferentially wandering, transient deformation (wandering wave) of the wall of the radially deformable frusto-cone body. These oscillations tend to increase and reach a resonance state and then cyclically and rapidly deform the entire frusto-cone body in relation to the withdrawal rim, e.g. when the local deformation orbits with high frequency. In a worst case, the entire braking zone could be lifted from the withdrawal rim by these resonance oscillations, consequently influencing the braking effect on the yarn in non-controlled fashion.
It is an object of the invention to provide a yarn feeder having a yarn brake and respectively a yarn brake per se for example known from EP 2 213 776 A1 performing optionally even when processing delicate yarns. In textile machines with intermittent yarn insertion the yarn feeder or the yarn brake in the yarn feeder should generate a desirably substantially identical and reproducible yarn tension profile from one machine cycle to the next, and on a continual basis. In textile machines with non-intermittent yarn insertion the yarn feeder or yarn brake should generate a stable, constant yarn tension continually over time. Part of the object is to reduce undesirable oscillations of the frusto-cone body during operation of the yarn feeder, or ideally to extinguish or suppress oscillations completely and, at the same time, to maintain the excellent braking performance, i.e. provide a substantially self-oscillation safe yarn brake.
These objects are achieved by the features of claims 1 and 9.
The oscillation damper carried by the frusto-cone body of the yarn brake considerably reduces or even extinguishes oscillations of the frusto-cone body caused by the orbiting local deformation of the wall of the frusto-cone body during operation of the yarn feeder and widely suppresses a resonance state in particular even when processing delicate yarns with high yarn withdrawal speeds. The oscillation damper comprises a generally annular counter-mass body and a circumferentially continuous intermediary portion of elastic material connecting the counter-mass body and the frusto-cone body. In the feeder the oscillation damper is arranged outside the braking nip so that it does not obstruct appropriate braking of the yarn in the yarn brake. Oscillation energy transmitted from the frusto-cone body and its orbiting local deformation into the intermediary portion will be consumed or dissipated by at least deformation of the elastic material of the intermediary portion which in turn is backed up by the counter-mass body which either does not oscillate or even carries out oscillations different from the oscillations of the frusto-cone body such that the elastic material in the intermediary portion is forced to permanently work and dissipate or consume energy. This effect suppresses the occurrence of a resonancy state in the frusto-cone body the braking zone of which thus remains in contact with the withdrawal rim except at the location where the yarn passes the braking nip. As, by virtue of the influence of the oscillation damper the braking zone will not be partly or totally released from the withdrawal rim, the excellent yarn braking performance of the yarn brake will be maintained even when processing delicate yarns with high yarn withdrawal speeds. For example, due to a predetermined relationship between the oscillation frequencies or because of different resonance frequencies of the frusto-cone body and the counter-mass body, and/or because the counter-mass body might be excited to oscillate by the transmitted oscillation energy from the frusto-cone body, the counter-mass body perfectly backs up the intermediary portion which in turn has to work by its elasticity and damping property and thus suppresses or extinguishes the oscillations of the frusto-cone body or hinders a development of a tendency of the frusto-cone body to reach a resonance state.
Preferred and alternative embodiments of the invention are defined in the depending claims.

Brief description of the drawings:

Fig. 1: is an axial section view of a yarn feeder comprising a yarn brake,
Fig. 2: is a perspective view of a yarn withdrawal side of the embodiment of the yarn brake shown in Fig. 1,
Fig. 3: is a perspective view of the opposite side of the yarn brake shown in Fig. 2,
Fig. 4: is a side view of the yarn brake,
Fig. 5: is a sectional view according to Fig. 4,
Fig. 6: is a detail view of the embodiment of the yarn brake shown in Figs 2 to 5, and
Figs 7 to 13: are detail sectional views of further embodiments of yarn brakes.

Fig. 1 shows a yarn feeder F with a stationary housing 1 containing a drive motor DM for driving a central shaft 2 to rotate inside the housing 1. An upstream, rear part of the shaft 2 is hollow and communicates with an obliquely outwardly extending yarn winding-on tube 3 fixed to a middle portion of the shaft 2, which winding-on tube 3 rotates together with the shaft 2. On a front part of the shaft 2 a storage body 4 is rotatably supported. The storage body 4 is prevented from co-rotating with the shaft 2 when the shaft 2 is driven be e.g. co-acting permanent magnets HM respectively arranged in the storage body 4 and in the stationary housing 1. The storage body 4 defines a substantially cylindrical storage surface 4a and has an axis X. The storage surface 4a serves to carry a schematically shown temporary yarn store YS formed of several, consecutively wound-on windings of a yarn Y. The yarn Y is pulled off e.g. from a not shown yarn bobbin arranged upstream of the yarn feeder F, passes through the rotating hollow shaft 2 and the winding-on tube 3, exits an outlet opening 3a of the winding-on tube 3, and is put on and wound up in the yarn store YS on the storage surface 4a.
The yarn Y is consumed by a not shown textile machine (e.g. a projectile weaving machine, a rapier weaving machine, a knitting machine, etc.) by being withdrawn from the yarn store YS overhead of the withdrawal rim 4b (which, preferably is bevelled or rounded) and through a stationarily fixed yarn output eyelet 5 located coaxially with the axis X of the storage surface 4a and stationarily supported in a bracket 1 a extending from the stationary housing 1 alongside the storage surface 4a, and further into the textile machine.
The yarn feeder F is equipped with a yarn brake B details of which will be explained in the following.
The yarn brake shown and explained is a non-restricting embodiment. Instead other not shown yarn brake designs could be used, provided that those have a frusto-cone body 9 which is deformable in radial direction and is axially yieldably pressed against the withdrawal rim 4b of the storage body 4.
In the embodiment of the yarn brake B in Figs 1 to 6 a basket-shaped structure 6 having an outer ring portion 6a, three spoke portions 6b1, 6b2, 6b3 and an inner ring portion 6c is snapped with its outer ring portion 6a into a holder 7. The holder 7, preferably, is adjustable in axial direction along the bracket 1 a. These adjustments vary the axial distance between the holder 7 and the withdrawal rim 4b of the storage body 4, e.g. for setting a desired basic yarn tension for the yarn Y when withdrawn from the storage surface 4a and through the yarn brake B.
The basket- shaped structure 9b, 6 encloses and co-acts with a ring-shaped body 8 carrying a small diameter end 10, 9b of a frusto-cone body 9 defining the so-called braking body of the yarn brake B. The frusto-cone 9 has a large diameter end 11 at the upstream side (seen in yarn withdrawal direction). The basket-shaped structure 6 being supported by holder 7 resiliently (elastically) forces an inner surface 12 of the frusto-cone body 9 coaxial with the axis X of the storage body 4 into pressing contact with the withdrawal rim 4b. The inner surface 12 of the frusto-cone body 9 defines a circumferentially continuous braking zone BZ between the large and small diameter ends 9a, 11. The frusto-cone body 9 is positioned coaxial with the axis X and is pressed by the ring-shaped body 8 resiliently against the withdrawal rim 4b. The braking zone BZ and the withdrawal rim 4b commonly and define a braking nip N for the yarn Y.
In the embodiment shown in Figs 2 and 3 the axially resilient force on the frusto-cone body 9 is generated in way known per se, disclosed e.g. in EP 1 807 563 A1 , namely by a system of two co-actuating mutually repelling ring-shaped permanent magnets PM1, PM2 fixed in annual seats in the ring-shaped body 8 and the inner ring portion 6c of the basket-shaped structure 6. The repelling force generated between the basket-shaped structure 6 and the ring body 8 is kept under guidance controlled by three guiding pins 8a, 8b, 8c, one ends of which are fixed at an outer rim of the ring-shaped body 8, while the other ends of the guiding pins are slidable in axial guiding holes 8A, 8B, 8C provided in the inner ring portion 6c of the basket-shaped structure 6. The small diameter end 10, 9b of the frusto-cone body 9 e.g. may be connected at 10 to the ring-shaped body 8 of a snap-in connection. A yarn guiding ring of wear resistant material, e.g. steel, having a smooth surface, may be attached to the inner periphery of the ring-shaped body 8 and serves to deflect the withdrawn yarn Y exiting the braking nip N essentially in the direction of a theoretical prolongation of the axis X.
Other embodiments of such yarn brakes having a frusto-cone body as well may be implemented in a yarn feeder and may be designed according to the invention. In those embodiments the axially resilient force on the frusto-cone body may be achieved by other means, for example by tensioning springs as e.g. disclosed in EP 0 884 263 B1 , or by an elastic diaphragm.
As mentioned, the circumferentially continuous braking zone BZ mechanically co-acting with the withdrawal rim 4b is defined on the inner surface 12 of the frusto-cone body 9. The braking zone BZ is kept in resiliently forced contact with the withdrawal rim 4b constituting the braking nip N through which the yarn Y is withdrawn. In the embodiment shown, the frusto-cone body 9 has a straight generatrix and e.g. a cone angle of about 30° (cone tip angle of about 120°). The generatrix does not need to be straight. The cone angle may be selected differently as well.
The frusto-cone body 9 may consist of a high performance thermoplastic polymer such as a polyketone composition, selected from the following polyketone group: polyetheretherketone (PEEK), polyaryletherketone (PAEK), polyetherketoneketone (PEKK).
However, a rich variety of material exists which can be used for the frusto-cone body 9, for example a polyester, or a composite material, e.g. carbon fibre reinforced plastics, etc. Many other examples of suitable materials are disclosed in the prior art of this technical field.
The polyketone frusto-cone body 9 mentioned above may have a wall thickness ranging between about 0.15 mm and 0.5 mm.
In the embodiments shown the frusto-cone body 9 of the yarn brake B carries an essentially annular oscillation damper 14 provided to suppress or reduce oscillations of the frusto-cone body 9, and, in particular, to suppress that the frusto-cone body 9 reaches a resonance state during operation of the yarn feeder F.
In the embodiments in Figs 1 to 8 and Figs 10, 11, the large diameter end 11 of the frusto-cone body 9 is associated or connected with a circumferentially continuous either unitary or multi-piece and generally frustoconical ring collar 14ab. The ring collar 14ab is made of an elastic material, preferably an elastomer and contains a substantially annular counter-mass body 14a and a circumferentially continuous intermediary portion 14b. Elastomers as polyurethane have proven to be excellent. Other kinds of elastic material, for example silicone rubber may be used as well. In the presently preferred case polyurethane may be used with a wall thickness of the ring collar 14ab of about 1 mm.
In the embodiment shown the frusto-cone body 9 has a length of about 4 cm in its generatrix direction and a weight of about 8 grams. The ring collar 14ab has a length of about 1.5 cm in generatrix direction and a total weight, including a lip 14e by which the ring collar 14ab overlaps (reference number BO, explained later) the frustocone body 9 of about 16 grams. The weight of a free portion of the ring collar 14ab extending generally outwardly from the large diameter end 11 of the frusto-cone body 9 is in this case estimated to be about 10 grams.
According to the invention the ring collar 14ab acts as a counter-mass oscillation damper in relation to the frusto-cone body 9 by virtue of inherent elasticity at least of the intermediary portion 14b and by an elastic connection e.g. with the large diameter end 11 of the frusto-cone body 9.
In operation of the yarn feeder F, when the yarn Y is withdrawn through the braking nip N and into the textile machine (not shown) the location where the yarn Y passes the braking nip N is rotating around the withdrawal rim 4b. Consequently, the wall of the frusto-cone body 9 is locally deformed at this location, such that a wandering wave of deformation occurs in the frusto-cone body 9. The rotating wave causes oscillations in the frusto-cone body 9. The oscillation damper 14 reduces or extinguishes these oscillations of the frusto-cone body 9 and advantageously suppresses that the oscillations reach a resonance state. The counter-mass 14a backs up the intermediary portion 14b which by deformation dissipates oscillation energy and may even impart inwardly directed damping forces at least on the frusto-cone body 9. The elastic material in the intermediary position 14b may be selected to have good oscillation damping properties..
In the embodiment shown the ring collar 14ab is a single or unitary component of elastic material, and comprises the counter-mass body 14a and the intermediary portion 14b, here both of elastic material. The intermediary portion 14b elastically attaches the counter-mass body 14a to the frusto-cone body 9. Elasticity and damping properties in the oscillation damper 14 thus in this case existing (inherent) in the whole unitary ring collar 14ab, will consume or dissipate or absorb oscillations or the energy of the undesirable self-oscillations arising in the frusto-cone body 9 and in the entire system.
In this way, the frequency with which the frusto-cone body 9 would oscillate in absence of the oscillation damper 14, while being under continuous impact by the withdrawn yarn Y moving with high speed in a spiral-like cyclical manner through the braking nip N, will be reduced to a minimum, or under ideal circumstances, will even be completely extinguished.
In Figs 9 and 12 the counter-mass body 14a is a circumferentially continuous ring e.g. with square cross-section. The ring may be of the same elastic material as the intermediary portion 14b. Instead it could be made of an inelastic material or of an at least less elastic material than the elastic material of the intermediary portion 14b, for example, of a PC (polycarbonate) plastics, or it could even be of metal, preferably of light metal, e.g. aluminium. However, the intermediary portion 14b is still and has to be of elastic or highly elastic material, for example elastomer. Its thickness may decrease with increasing distance from the frusto-cone body 9. In these embodiments the counter-mass body 14a and the intermediary portion 14b may be separate components which are connected with each other in an appropriate way (multi-piece structure) for example by means of a durable glue. In the case that both parts are e.g. moulded plastic parts, they could even be joined in an injection moulding process.
Thus, the oscillation damper 14 working as a counter-mass damper, the ring collar 14ab through its elastic connection with the frusto-cone body 9, suppresses undesirable self-oscillations of the frusto-cone body 9 that might otherwise negatively influence the braking effect on the yarn Y, e.g. making the resulting yarn tension in the withdrawn yarn Y unstable. Based on the co-action between the frusto-cone body 9 and the oscillation damper 14 via the bridging or inherent elasticity and damping property in the system, the kinetic energy of the undesirable self-oscillations of the frusto-cone body 9 will be extensively, or in an ideally tuned case, completely dissipated which leads to an expedient stabilisation of the yarn tension generated by the yarn brake B in the withdrawn yarn Y.
The inner surface of the oscillation damper 14, e.g. of the ring collar 14ab may have a preferably small, circumferentially continuous lip 14c, bounding an annular pocket seat 14d at the intermediary portion 14b within which pocket seat 14d the large diameter end 11 of the frusto-cone body 9 is fitted such that the ring collar 14ab is loosely kept on the frusto-cone body 9 and is easily removable. This type of gentle connection is especially suitable also because it does not negatively influence the expedient dynamic properties and the desired braking performance of the radially deformable but axially relatively stiff frusto-cone body 9.
In other embodiments of the yarn brake B the ring collar 14ab may be attached to the frusto-cone body 9 differently, e.g. by a durable glue, a double-adhesive tape, or even by vulcanisation, provided that the ring collar is made of a material being or including rubber.
In the embodiments shown in Figs 6 to 11 the ring collar 14ab overlaps, in generatrix direction, with another, preferably circumferentially continuous, lip 14e the outer surface 13 on a comparatively large (frustoconical) portion BO close to the large diameter end 11 of the frusto-cone body 9. Preferably, the lip 14e extends on the outer surface of the frusto-cone body 9 up to or even somewhat beyond (downstream in the yarn withdrawal direction) the region of the braking zone BZ, with which the inner surface 12 of the frusto-cone body 9 is may come in resiliently forced contact with the rounded withdrawal rim 14b, when the yarn brake B is installed in a yarn feeder F. The lip 14e, however, may be dispensed with in other not shown embodiments..
The backing up of a relatively large portion of the outer surface 13 of the frusto-cone body 9 by the overlapping lip 14e has proven to contribute positively to the desired stabilisation of the dynamic behaviour of the frusto-cone body 9 in operation of the yarn brake B.
The stabilising effect of the ring collar 14ab may be further improved if (Figs 4 to 6) the ring collar 14ab is designed with a circumferential continuous ring flange 15 at its free end, having one or a series of portions extending in different directions all of them differing from the straight generatrix direction of the frusto-cone body 9 and also of the main portion of the ring collar 14ab. This ring flange 15 has proven to have an expedient positive stiffening effect on the ring collar 14ab and form part of the counter-mass body 14 integrated into the ring collar 14ab..
In a not shown embodiment the ring flange 15 may be substantially radial with a radial extension in the range of some millimetres, e.g. about 5 mm.
In a presently preferred embodiment (Figs 1 to 6) the ring flange 15 (or a part thereof) can have a direction which is so to speak inverse to the generatrix direction of the main part of the ring collar 14ab, and with a rounded transition region 15a between the main portion of the ring collar 14ab and the ring flange 15.
In Fig. 7 the ring flange 15 has an S-shaped profile or cross-section.
Fig. 8 the ring collar 14ab comprises a larger amount of mass than in the earlier shown embodiment, by having the ring flange 15, enlarged and essentially circular in cross-section, at its free end, at least as part of the counter-mass body 14a.
Figs 10 and 11 show embodiments where the ring collar 14ab of the oscillation damper 14 has a U-shaped, respectively a Z-shaped profile or cross-section with free portions of the ring collar 14ab extending frontwards alongside and essentially in parallel with the outer surface 13 of the frusto-cone body 9.
In Figs 12 and 13 the oscillation damper 14 is carried by the outer surface 13 of the frusto-cone body 9 in a region between the large and small diameter ends 11, 9b, e.g. in the vicinity of the region of the braking zone BZ .
In Fig. 13 the ring collar 14ab including the counter-mass body 14a and the intermediary position 14b has the form of a circumferentially continuous dual-leg tongue or lip of elastic material, e.g. an elastomer joined to the outer surface 13 of the frusto-cone body 9, for example by a durable glue. The oscillation damper 14 is located in an area even somewhat downstream (seen in yarn withdrawal direction) of the region of the braking BZ with which the inner surface 12 of the frusto-cone body 9 may be brought in resiliently forced contact with the withdrawal rim 4b, when installed in a yarn feeder F.
The embodiment in Fig. 12 has the oscillation damper 14 substantially at the same location of the outer surface 13 of the frusto-cone body 9 as shown in Fig. 13, i.e. downstream of the area of the braking zone BZ. Here, however, a circumferential continuous counter-mass body 14a with the shape of a ring e.g. having a square cross-section e.g. of inelastic material, e.g. polycarbonate plastics, metal or light metal, and the intermediary portion 14b of elastic material, e.g. an elastomer, constitute the oscillation damper 14, in which a part (lip 14e) of the intermediary portion 14b is attached to the outer surface 13 of the frusto-cone body 9, for example by a durable glue. The counter-mass body 14a may be connected to the intermediary portion 14b by gluing or by co-injection moulding.
The frusto-cone body 9 and the oscillation damper 14 may be a prefabricated separate structure unit or may be assembled when, before or after the frusto-cone body 9 is mounted in the ring-shaped body 8. In the case that the frusto-cone body 9 has to be replaced, the oscillation damper 14 may be used again, e.g. of the embodiments of Figs 1 to 11. The respective yarn brake B as well may be a prefabricated separate structural unit (spare part for yarn feeders F).

Claims

Yarn feeder (F) for textile machines, in particular for rapier and projectile weaving machines and knitting machines, comprising a stationary, substantially cylindrical storage body (4) for a temporary yarn store (YS), the storage body (4) having a circumferentially continuous withdrawal rim (4b), a yarn brake (B) including a hollow frusto-cone body (9) which is deformable in radial direction but essentially stiff in axial direction and defines a circumferential continuous braking zone (BZ) on its inner surface (12), and is resiliently forced against the withdrawal rim (4b) coaxial with an axis (X) of the storage body (4) and kept in resiliently pressed contact with the withdrawal rim (4b), the withdrawal rim (4b) and the braking zone (BZ) forming a yarn braking nip (N), characterised in that the frusto-cone body (9) carries at least one essentially annular oscillation damper (14) arranged at the frusto-cone body (9) outside the braking nip (N).
Yarn feeder according to claim 1, characterised in that the oscillation damper (14) comprises an annular counter-mass body (14a) and an intermediary portion (14b) of elastic material, preferably an elastomer, connecting the counter-mass body and the frusto-cone body (9), the counter-mass body and the intermediary portion, preferably, forming a unitary or a multi-piece ring collar (14ab).
Yarn feeder according to claim 2, characterised in that the counter-mass body (14a) at least in parts, consists of either the same or a different elastic material as the intermediary portion (14b) or of inelastic material or metal.
Yarn feeder according to claim 2, characterised in that the intermediary portion (14b) is continuous in circumferential direction, extends outwardly from the frusto-cone body (9) and, preferably, has outwardly decreasing thickness.
Yarn feeder according to claim 1, characterised in that a large diameter end (11) of the frusto-cone body (9) carries the oscillation damper (14).
Yarn feeder according to claim 1, characterised in that the oscillation damper (14) is connected, preferably by gluing or vulcanisation, with an outer surface (13) of the frusto-cone body (9), preferably, in a circumferential region arranged between the region of the braking zone (BZ) and a small diameter end (9b) of the frusto-cone body (9).
Yarn feeder according to claim 2, characterised in that the counter-mass body (14a) comprises an outer circumferentially continuous flange (15) which, preferably, extends in its cross-section from the intermediary portion (14b) substantially radially straight or curved.
Yarn feeder according to claim 2, characterised in that the intermediary portion (14a) is extended by a circumferentially continuous lip (14e) overlapping a portion (BO) of the outer surface (13) of the frusto-cone body (9) between the large diameter end (11) and the region of the braking (BZ), preferably the lip (14e) extending up to or beyond the region of the braking zone (BZ).
Yarn brake (B) for a yarn feeder (F), the yarn brake (B) comprising a hollow frusto-cone body (9) which is deformable in radial direction but essentially stiff in axial direction, an inner surface (12) of which extending between a small diameter end (9b) and a large diameter end (11) defining a circumferentially continuous braking zone (BZ), characterised in that the frusto-cone body (9) carries at least one essentially annular oscillation damper (14).
Yarn brake according to claim 9, characterised in that the oscillation damper (14) comprises an annular counter-mass body (14a) and an intermediary portion (14b) of elastic material, preferably an elastomer, connecting the counter-mass body and the frusto-cone body (9), the counter-mass body and the intermediary portion, preferably, forming a unitary or a multi-piece ring collar (14ab).
Yarn brake according to claim 9, characterised in that the oscillation damper (14) has an inner circumferentially continuous lip (14c) bounding a pocket seat (14d) of the oscillation damper (14) into which pocket seat (14d) the large diameter end (11) of the frusto-cone body (9) is releasably inserted.
Yarn brake according to claim 10, characterised in that the counter-mass body (14a) at least in parts, consists of either the same or a different elastic material as the intermediary portion (14b) or of inelastic material or metal.
Yarn brake according to claim 10, characterised in that the intermediary portion (14b) is continuous in circumferential direction, and, preferably, has outwardly decreasing thickness.
Yarn brake according to claim 9, characterised in that the large diameter end (11) of the frusto-cone body (9) carries the oscillation damper (14).
Yarn brake according to claim 9, characterised in that the oscillation damper (14) is connected, preferably by gluing or vulcanisation, with an outer surface (13) of the frusto-cone body (9), preferably, in a circumferential region arranged between the region of the braking zone (BZ) and a small diameter end (9b) of the frusto-cone body (9).
Yarn brake according to claim 10, characterised in that the counter-mass body (14a) comprises an outer circumferentially continuous flange (15) which preferably extends straight or curved substantially radially with respect to the intermediary portion (14b).
Yarn brake according to claim 10, characterised in that the intermediary portion (14a) has an outer circumferentially continuous lip (14e) overlapping a portion (BO) of the outer surface (13) of the frusto-cone body (9) between the large diameter end (11) and the region of the braking (BZ), preferably the lip (14e) extending up to or beyond the region of the braking zone (BZ).