WO2007079962A1

WO2007079962A1 - Thread delivery unit and brake element

Info

Publication number: WO2007079962A1
Application number: PCT/EP2006/012485
Authority: WO
Inventors: Per Ohlson
Original assignee: Iro Ab
Priority date: 2006-01-09
Filing date: 2006-12-22
Publication date: 2007-07-19
Also published as: DE102006001125A1

Abstract

A direct snap-action connection is provided between the brake body (B) and the holding ring (R) on a thread delivery unit (L) having a housing (22), a rotatable winding element (25, 26), a stationary storage body (10) and a thread brake which is mounted on a housing outrigger (23) and has a flexible, rotationally symmetrical brake body (B), in the form of a truncated cone face (1), which interacts coaxially with a take-off end (11) of the storage body (10) and on which a rigid, coaxial holding ring (R) acts as a support (13) of the thread brake, which direct snap-action connection can be produced and released for inserting and removing the brake body (B) in each case by the action of force from the outside, and positions the brake body in the holding ring (R) in a manner which is secured against falling out but is exchangeable. Here, the brake body (B) is equipped with an elevated or depressed snap-action element (V).

Description

Thread delivery device and brake body

The invention relates to a thread delivery device according to the preamble of claim 1 and a brake body according to the preamble of claim 11.

In the thread brake known from US 6 164 580 A, the brake body is loosely inserted into the retaining ring, so that the brake body is held in the operative condition of the thread brake by resilient axial pressure on the retaining ring at the withdrawal end of the storage body of the thread delivery device. The brake body is made of transparent plastic material, for example. Since sometimes the brake body is moved axially from the system on the storage body into a so-called gap position, for example in order to be able to thread a new thread, or for cleaning purposes, the brake body can fall out of the retaining ring due to the loose attachment or tilt so far that it can be threaded or cleaning hindered. The brake body made of plastic often also sticks to the storage body when the thread brake is adjusted to the gap position. This pulls the brake body out of the retaining ring so that it falls off. These problems can be avoided if the brake body is fixed in the retaining ring by an adhesive connection or a clamp connection. However, since the brake body is a wearing part, which may have to be replaced relatively frequently, such a fuse makes replacement difficult or the retaining ring must also be replaced.

The brake body known from EP 1 164 103 A, FIG. 3, for a thread brake for weft thread delivery devices is clamped with an extension tube at the small-diameter end between inner and outer parts of the retaining ring that are glued or locked together. If the brake body has to be replaced as a wearing part, this attachment makes it difficult to replace it quickly or is replaced by the retaining ring, which can be difficult to remove.

From EP 0 963 335 A it is known to insert the metallic conical brake ring of a thread brake into one or more pockets of a ring membrane which transmits the resilient axial force from the retaining ring to the brake ring. The ring membrane is firmly connected to the retaining ring. The brake ring is interchangeable thanks to this floating positioning.

From PCT-EP2005 / 009674 with older seniority a plastic brake body for a knitting delivery device is known, on the small-diameter truncated cone end a spherical support part is integrally formed. The brake body with the spherical support part is placed in a universal joint retaining ring and, if necessary, only loosely positioned by pressing on the storage body.

In the thread brake proposed in DE 10 2004 045 725 with an older seniority, the plastic brake body is resiliently acted upon from the stationary support via the holding ring by a magnet arrangement. The retaining ring is stored in such a way that it cannot fall out. The brake body with the extension tube is only inserted or glued into the retaining ring.

The invention has for its object to provide a yarn delivery device and a brake body, in which the functional reliability of the thread brake is improved despite the possibility of a simple replacement of the brake body.

The object is achieved with the features of claim 1 and claim 11.

The snap connection prevents the brake body from falling out of the retaining ring even when the brake body is not pressed against the storage body. When the thread brake is adjusted to the gap position, e.g. for threading a new thread or for cleaning, the force with which the brake body tends to stick to the storage body is overcome so that the brake body is properly released from the storage body and assumes a position in which does not hinder threading or cleaning. The brake body is installed by pushing it firmly into the retaining ring. The retaining ring does not need to be replaced when the brake body is replaced. A certain amount of force must be exerted that is greater than the forces that act on the brake body when the thread brake is operating in the pull-out direction. The snap connection expediently has an all-round play of movement of the brake body in the retaining ring. This means that the brake body is interchangeably and securely positioned due to the snap connection, but can perform its own movements relative to the retaining ring, which may be important for the braking function in the operative condition. The movement play also makes it easier to insert and remove the brake body.

Interacting snap elements are expediently provided on the retaining ring and on the brake body, but these interact with the play of movement.

At least one snap element is attached or formed on the brake body on the truncated cone jacket, so that the truncated cone jacket can even be positioned in the retaining ring so that it cannot fall out.

In another embodiment, the brake body has a coaxial extension tube at the small-diameter end of the truncated cone. The extension tube can be inserted into the retaining ring and has at least one snap element with which the brake body can be snapped into the retaining ring.

If the brake body is made of plastic, as is often the case in knitting machines, and the storage body is made of metal, an adhesive force can develop, for example, due to electrostatic influences between the brake body and the storage body, which is a hindrance when the thread brake is to be adjusted into the gap position. In order to prevent the brake body from sticking to the storage body, the extent of the force to release the snap connection is set greater than this adhesive force, so that the brake body can be reliably brought into the gap position.

In terms of production technology, the snap element on the brake body is oriented either outwards or inwards, while the snap element interacting therewith is designed in the opposite manner in the retaining ring. In an expedient embodiment, the extension tube of the brake body is inserted through a tube section in the retaining ring and snapped between the shoulders of the retaining ring.

The snap element is expediently arranged on the extension tube at a distance from its free end, so that the free end of the extension tube forms an insertion projection for guiding the extension tube through the tube section. This particularly facilitates the insertion of the brake body into the retaining ring.

In an expedient embodiment, the retaining ring has a flange which widens essentially with the angle of the truncated cone for supporting the small-diameter end region of the truncated cone. This support can be advantageous for the braking function. In addition, the brake body, if it is a truncated cone jacket without an extension tube, can be snapped directly into this flange with the small-diameter end region.

The outward or inward-facing snap element on the truncated cone jacket or on the extension tube makes it very easy to snap the brake body into a retaining ring of the support of the support structure of the thread brake, in such a way that the brake body is always interchangeable, but always properly secured. The snap element means only a negligible additional effort in the manufacture of the brake body. This is important because the brake body as a wearing part should be as inexpensive as possible. The snap element does not interfere with the function of the brake body, but it creates the optimal conditions for releasably fixing the brake body in the retaining ring without having to use tools or other aids.

In an expedient embodiment of the brake body, the snap element is a bead which is continuous or interrupted, raised or deepened. This training is particularly well suited for snapping with an abutment of the retaining ring. Furthermore, the bead can be formed very easily. In another embodiment, the snap element consists of several individual bumps, which are distributed in the circumferential direction around the truncated cone shell or the extension tube.

In a further, expedient embodiment, the snap element comprises a plurality of tabs which are notched out of the wall of the extension tube and which cooperate with the retaining ring like barbs.

In one embodiment, the bead, each bead portion or single bump on the wall is e.g. of the extension tube attached. That is, the bead or the bead sections or the individual bumps are separately manufactured plastic elements which e.g. are glued or fixed differently.

Particularly expediently, however, the bead or each bead section or each individual hump consists of the material of the truncated cone shell, or extension tube, in which the wall is deformed, for example by plastic cold or hot deformation.

In one embodiment, the snap element is arranged at a distance from the free end of the extension tube. This has the advantage that the free end of the extension tube can be used as an insertion approach when mounting the brake body.

In a further embodiment that is easy to manufacture, the holding projection is a continuous or interrupted end widening. The expansion is expediently rounded.

The bead or each bead section or each individual bump can have a convex curve or an approximately trapezoidal cross-sectional shape in an axial section of the brake body. This design simplifies the insertion or removal of the brake body into or out of the retaining ring, but a certain resistance must be overcome in each case. The brake body can consist, for example, of an amorphous plastic material for knitting thread material. Examples of such plastic materials are PVC or ABS. The brake body is particularly advantageously formed in one piece by vacuum forming from a flat blank. The plastic can be transparent or opaque or colored. However, the brake body could also consist of other materials or, if necessary, have a wear-resistant coating in the brake area, for example for woven weft material.

The height or depth of the snap element and its axial extent can be between about 1 to 5% of the outside diameter.

Another important indication is that a circumferential shoulder is molded into the brake body in the transition area from the small diameter end of the truncated cone shell into the extension tube. This circumferential shoulder with its inside serves to deflect the thread and with its outside to position the brake body in the retaining ring, not only for the braking operation, but also for the snap connection if necessary.

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

1 is a side view of an embodiment of a brake body,

2 shows a side view of a further embodiment,

3 shows a side view of a further embodiment,

4 shows a side view of a further embodiment,

5 is a perspective view of the embodiment of FIG. 1,

6 is a perspective view of an alternative embodiment, 7 is a side view of the embodiment of FIG. 4,

8 is a side view of the thread brake body mounted in a retaining ring (in an axial section) to constitute a sub-assembly of a thread brake,

9 shows the two components of the subassembly from FIG. 8 in the ready-to-install or in the exchange state,

10 shows a further embodiment of the subassembly,

11 shows a further embodiment of the subassembly, and

Fig. 12 schematically shows a side view of a yarn delivery device, partly in section.

A brake body B e.g. 1 for knitting or weaving threads consists of a truncated cone jacket 1 with a large-diameter end 2, a small-diameter end 3, and an inner surface defining a braking surface 4. A coating is possibly applied to the braking surface 4. An essentially cylindrical extension tube 5 is formed on the small-diameter end 3, preferably in one piece, which ends at a free end 6. At a distance from the small-diameter end 3 of the truncated cone 1 and also at a distance from the free end 6 of the extension tube 5, a snap element V oriented in the circumferential direction emerges in FIG. 1 from the outer circumference of the extension tube 5. Brake body B is flexible, i.e. deformable in the radial direction, but relatively stiff in the axial direction.

1, the snap element V is a raised bead W which is continuous in the circumferential direction and has a semicircular or generally convexly rounded or approximately trapezoidal cross section. The bead W can be a separate part and fixed on the extension tube 5, or is expediently formed directly from the material of the extension tube 5. For example, the bead W is formed by plastic cold or hot deformation of the wall of the extension tube 5 to the outside. The bead W need not necessarily be continuous in the circumferential direction, but could also have at least one or more interruptions. The height b as well as the axial extent a can be between approximately 1 to 5% of the outer diameter d of the extension tube 5 or the small-diameter end 3. The brake body B is expediently a one-piece molded plastic part, which is produced, for example, by vacuum forming from a flat blank. The snap element V can be molded during the manufacture of the thread brake body B, or can only be attached subsequently, its distance from the small-diameter end 3 being adapted to the dimensioning in a retaining ring, not shown, of a support structure of the thread brake in which the brake body is used.

The thread brake body B in FIG. 2 differs from that of FIG. 1 in that the snap element V is formed from a plurality of individual bumps H distributed in the circumferential direction, which are either formed and attached separately from the material of the extension tube 5 or from it.

The embodiment of the brake body B in FIG. 3 differs from the previously explained in that the snap element V is formed by a plurality of notches K distributed in the circumferential direction outward from the wall of the extension tube 5. These notches can point like barbs towards the truncated cone jacket 1.

The brake body B in FIG. 4, as the snap element V, has a widening E directly at the free end 6 of the extension tube 5. The widening E can be continuous or interrupted in the circumferential direction. The expansion E is expediently rounded.

FIG. 5 is a perspective view of a brake body B, which largely corresponds to the embodiment of FIG. 1. In addition, a circumferential shoulder 8 is formed in the transition area from the truncated cone 1 into the extension tube 5. The figure also shows how the bead W is subjected to pressure from the inside out is shaped so that there is a groove on the inside. Between the free end 6 and the bead W, the end section of the extension tube 5 forms an insertion extension 7 for easy mounting of the brake body in the support structure of the thread brake.

Fig. 6 is a perspective view of a brake body B ₁ on the extension tube 5 as a snap element V of the bead W protrudes outwards so that it ends directly with the free end 6 of the extension tube 5. A circumferential shoulder 8 is formed in the transition area between the truncated cone and the extension tube 5.

The brake body B in Fig. 7 largely corresponds to that of Fig. 4, ie, the snap element V is a continuous expansion E in the circumferential direction at the free end 6 of the extension tube 5. The reference number 9 indicates the back of the circumferential shoulder 8 between the truncated cone jacket 1 and the extension tube 5.

The brake body B in FIGS. 1 to 7 is expediently made of an amorphous plastic material, for example by vacuum deformation of a flat blank. Examples of usable plastic materials are PVC and ABS.

FIG. 8 illustrates a subassembly U of a thread brake F for a knitting or weaving thread delivery device L, which is only indicated. A front end of a storage body 10 is shown in broken lines by the delivery device L. At the front end, the storage body 10 has a rounded trigger edge 11, which is converted into a thread storage area 12. The brake body B of the sub-assembly U is securely positioned in a retaining ring R by a snap connection, that is to say positioned such that it cannot fall out automatically, but a certain amount of force in the direction of an arrow 18 is required to remove the brake body, for example for replacement to loosen the retaining ring R. To mount the brake body B in the retaining ring R, it only needs to be pressed in with a certain amount of force in the opposite direction until it is securely positioned with the aid of the snap element V. The snap element V of the brake body interacts positively with a snap element V of the retaining ring R. In the working position A of the thread brake F indicated above in FIG. 8, the retaining ring R is pressed axially against the front end of the storage body 10 by an energy store 14 relative to a stationary support 13, for example of the delivery device L, so that the one formed by the inner wall of the brake body B Braking surface 4 rests on the trigger edge 11. A knitting or weaving thread Y _1, which is stored in adjacent turns on the storage surface 10, is pulled over the withdrawal end 11 and along the braking surface 4, the withdrawn thread Y circulating clockwise between the withdrawal edge 11 and the braking surface 4. The thread Y drawn off then no longer touches the inner surface of the truncated cone shell 1, but is deflected on the shoulder 8 before it is pulled through the extension tube 5 and the retaining ring R.

The brake body B rests with the back 9 of the shoulder 8 against a shoulder 16 inside the retaining ring R, while the snap element V is a snap element, e.g. a shoulder 15 of the retaining ring R engages behind. In this way, the brake body B is securely positioned in the retaining ring R even without contact with the storage body 10 by the snap connection. An all-round play 20 is provided in the snap connection between the brake body B and the retaining ring R. A certain amount of force is required to remove the brake body B from the retaining ring R, as well as to insert it into the retaining ring R. When inserting, the insertion protrusion 7 helps to simply thread the brake body and to be able to push it through a pipe section 21 which is between the shoulders 15 , 16 of the retaining ring R is formed (Fig. 9).

In FIG. 8, the retaining ring R is coupled to the stationary support 13 so as to be self-limited to such an extent that it cannot automatically detach itself therefrom, and so that when the thread brake F is adjusted into a gap position indicated at the bottom right in FIG. 8 G pulls the brake body B over the snap connection. In the gap position G, a gap 19 is formed, for example, between the trigger edge 11 and the braking surface 4, through which a new thread can be threaded or which is useful for cleaning purposes. Fig. 9 shows the situation of the sub-assembly U before assembly or after removal of the brake body B. The axial distance between the back 9 of the shoulder 8 of the brake body B and the snap element V should be such that it is slightly larger than the axial distance between the shoulders 15, 16 of the retaining ring R ₁ to allow a certain amount of movement in this direction as well. A rounded or approximately trapezoidal cross-section or outer contour of each snap element V facilitates the threading and pulling out of the brake body B into or out of the retaining ring R ₁ because the flanks of the snap element V act in the manner of insertion or extraction ramps. In the embodiment in FIG. 3, it may be necessary to tear off the tabs K in order to remove the brake body B from the retaining ring R, but this does not mean a disadvantage since the brake body B is thrown away anyway.

In a structurally simple and inexpensive manner, the brake body B, as a replacement part that is to be exchanged frequently, is prepared, thanks to its snap element V, for fail-safe positioning in the support structure of the thread brake, the snap connection making it easy to replace, and can be used without tools or other aids.

Fig. 10 illustrates a sub-assembly U from the retaining ring R and the brake body B, which is formed as in the previous figures from the truncated cone 1 and the coaxial extension tube 5, in such a way that it can enter into a snap connection with the retaining ring R. For this purpose, in contrast to the other embodiments, the snap element V is a groove or a recessed bead N in the extension tube 5, while the snap element V in the retaining ring R is an inwardly projecting bead W, which enters the groove N as soon as the brake body B to to be inserted with the small-diameter end 3 on the shoulder 16 through the pipe section 21. In this case too, the snap connection is designed in such a way that there is an all-round play of movement of the brake body in the retaining ring R.

The subassembly U in FIG. 11 differs from all the previous embodiments in that the brake body B only consists of the truncated cone jacket 1 there is, that is, without the extension tube 5, so that the brake body B ends with the small-diameter end 3 of the truncated cone 1. The snap element V is provided on or in the wall of the truncated cone 1, for example adjacent to the small-diameter end 3 or directly thereon, in order to make the snap connection with the snap element V (a rounded groove N) provided in the retaining ring R in the conical flange 17, as soon as the small-diameter end 3 abuts the shoulder 16 or is positioned close to it. Here, a construction as in FIG. 10 could be provided, ie the snap element V of the brake body can be designed as a recessed bead or groove, whereas the snap element V of the retaining ring R can be an inwardly projecting bead.

12 is a side view of a thread delivery device (schematic representation) for textile machines, for example for knitting machines or weaving machines. The thread delivery device L has a housing 22 with a housing extension 23. A rotatably drivable winding element 25, which contains an outlet eyelet 26 for the thread Y, is mounted on or in the housing 22. Furthermore, for example a drum-shaped storage body 10 is arranged on or in the housing 22 and is stationary relative to the rotating element 25. The storage body 10 receives, on its peripheral support surface 12, adjacent turns of the thread Y, which are formed by the winding element 25 when it rotates. The rounded trigger edge 11 adjoins the support surface 12 on the trigger side of the storage body. A thread brake F is supported on a carriage 31 in the housing bracket 23. The slide 31 can optionally be adjusted by means of a handle 32 along the housing arm 23. On the carriage 31, a support 13 of the thread brake F is attached, which has a support ring 30, a holding basket 29 and the support ring R for the brake body B. Between the retaining ring R and the support ring 30, for example, mutually repelling, conical permanent magnet rings 27, 28 are arranged, which act as energy stores for applying an axial pressure force to the brake body B and for centering it. Instead of the magnet arrangement, it would also be possible to provide another force storage device, for example with springs, membranes, or the like, which is able to generate an elastic axial contact force for the brake body B between the storage body 10 and the slide 31. The retaining ring R is arranged in the support ring 29 with play, but is arranged such that it cannot fall out of the support ring 29 to the left in FIG. 12. This positioning is not shown in Fig. 12. In the support ring R, the brake body B is interchangeably used, for example, according to FIGS. 1 and 8, and is positioned in a fail-safe manner by the snap connection between the snap elements V. The snap elements V are, for example, a raised bead W on the extension tube 5 of the brake body and a recessed groove N inside the support ring R.

The axial contact pressure of the brake body B is set, for example, by the positioning of the slide 31. In order to be able to thread a new thread or for cleaning purposes, the slide 31 in FIG. 12 can be adjusted to the right until the gap position G indicated in FIG. 8 with the gap 19 between the brake body B and the trigger edge 11 is reached. The brake body B then no longer contacts the storage body 10, but is loosely positioned on the retaining ring R by the snap connection with the movement play. The brake body B can then be easily replaced by overcoming the holding force of the snap connection by pulling on the brake body until the extension tube 5 has emerged from the retaining ring R. A new brake body B is installed in the reverse manner until the snap connection is restored. The movement play in the snap connection is otherwise eliminated in the braking condition of the thread brake shown in FIG. 12, since the axial pressure then presses the brake body firmly against the retaining ring R. When replacing the brake body B, the retaining ring R does not need to be replaced.

Claims

1. Thread delivery device (L) for textile machines, in particular for weaving machines or knitting machines, with a housing (22) on which a winding member (25, 26) is rotatable and a storage body (10) is mounted in a stationary manner, and one in a on a housing bracket ( 23) arranged support mounted thread brake (F), which has a flexible, rotationally symmetrical brake body (B) in the form of a truncated cone jacket (1) coaxially cooperating with a withdrawal end (11) of the storage body (10), on which a rigid, coaxial retaining ring (R ) acts on the support, characterized in that a direct snap connection is provided between the brake body (B) and the retaining ring (R), which can be produced and released by external force in each case by inserting and removing the brake body (B) and the brake body ( B) failsafe but interchangeable, positioned in the retaining ring (R).

2. Thread delivery device according to claim 1, characterized in that the snap connection has an all-round movement of the brake body (B) in the retaining ring (R).

3. Thread delivery device according to claim 1, characterized in that on the retaining ring (R) and on the brake body (B) with the movement play interlocking snap elements (V) are provided.

4. Thread delivery device according to claim 3, characterized in that at least one snap element (V) on the brake body (B) on the truncated cone jacket (1) is attached or molded.

5. Thread delivery device according to claim 3, characterized in that the brake body (B) at the small diameter end (3) of the truncated cone shell (1) has a coaxial, essentially cylindrical extension tube (5) which can be inserted into the retaining ring (R), and that at least one snap element (V) is attached or molded onto the extension tube (5).

6. Thread delivery device according to claim 1, characterized in that the brake body (B) made of plastic and the storage body (10) made of metal, and that the extent of the force for releasing the snap connection is set greater than one between the brake body (B) and the trigger end (10), e.g. due to electrostatic influences, effective adhesive force.

7. Thread delivery device according to claim 3, characterized in that the snap element (V) on the brake body (B) on the truncated cone jacket (1) or on the extension tube (5) relative to the axis (X) is oriented outwards or inwards, and that The associated snap element (V) in the interior of the retaining ring (R) engages behind the snap element (V) of the brake body (B) either positively from the outside or engages in the snap element of the brake body from the outside.

8. Thread delivery device according to claim 5, characterized in that the brake body (B) with the extension tube (5) between a shoulder facing the truncated cone (1) bearing shoulder (16) of the retaining ring (R) and an abutment, from the truncated cone jacket (1) pointing shoulder (15) is snapped into a pipe section (21) of the retaining ring (R) running between the shoulders (15, 16).

9. Thread delivery device according to claim 8, characterized in that the snap element (V) is arranged at a distance from the free end (6) of the extension tube (5), and that the free end (6) of the extension tube (5) has an insertion lug ( 7) for passing the extension tube (5) through the tube section (21) during the production of the snap connection.

10. Yarn feeding device according to claim 8, characterized in that the retaining ring (R) following the abutment shoulder (16) extends substantially to the cone angle of the frustoconical shell (1) expanding flange (17) _for, supporting the small-diameter end portion of the truncated cone (1).

11. Thread brake body (B) for a thread brake (F), in particular for a thread delivery device (L) ₁ , the brake body (B) being a rotationally symmetrical flexible cone Stump jacket (1), characterized in that on the truncated cone jacket (1) or on a coaxial, essentially cylindrical extension tube (5) at the small-diameter end (3) of the truncated cone jacket (1) at least one with respect to the axis (X) to the outside or inwardly oriented, circumferential snap element (V) is provided which is continuous or interrupted in the circumferential direction.

12. Brake body according to claim 11, characterized in that the snap element (V) is in a plane perpendicular to the axis (X) of the brake body (B) substantially continuous or interrupted, raised or recessed bead (W).

13. Brake body according to claim 11, characterized in that the snap element (V) comprises a plurality of individual bumps (H).

14. Brake body according to claim 11, characterized in that the snap element (V) comprises a plurality of tabs (K) notched out of the wall of the truncated cone shell (1) or of the extension tube (5).

15. Brake body according to claim 12 or 13, characterized in that the bead (W) or each individual hump (H) on the wall of the truncated cone shell (1) or the extension tube (5) is attached.

16. Brake body according to claim 12 or 13, characterized in that the bead (W) or each individual hump (H) is formed by a deformation of the wall of the truncated cone shell (1) or the extension tube (5), preferably by a plastic cold or Thermoforming of the wall.

17. Brake body according to claim 11, characterized in that the snap element (V) is arranged at a distance from the small-diameter end (3) or from the free end (6) or at this end (3, 6).

18. Brake body according to claim 11, characterized in that the snap element (V) is substantially perpendicular to the axis (X) of the brake body. th level is continuous or interrupted expansion (E) of the small-diameter end (3) or of the free end (6).

19. Brake body according to claim 12 or 13, characterized in that the bead (W) or each individual hump (H) in an axial section of the brake body (B) is convexly rounded or approximately trapezoidal.

20. Brake body according to at least one of the preceding claims, characterized in that the brake body (B) made of amorphous plastic, such as PVC or ABS, preferably, is formed by vacuum forming a flat blank.

21. Brake body according to at least one of the preceding claims, characterized in that the height or depth (b) and the axial extent (a) of the snap element (V) relative to the outside of the brake body (B) between 1 to 5% of the outer diameter (d ) of the small diameter end (3).

22. Brake body according to at least one of the preceding claims, characterized in that a circumferential shoulder (8) is provided in the transition region from the small-diameter end (3) of the truncated cone shell (1) into the extension tube (5).