EP1518810B1 - Yarn brake and textile machine and yarn feeding device equipped with such a yarn brake - Google Patents

Abstract

A yarn tension device has a holder, a bearing bolt with a shank (24) supported by an extension (26) and held between two brake blocks (33, 34). The brake pressure is regulated by a spiral spring (29) tensioning device and a block (39) at one end and a cap (20) at the other. The shank (24) slides axially within the surrounding holder (17). Also claimed are a commensurate textile machine and yarn feed.

Description

The invention relates to a yarn brake of the type specified in the preamble of claim 1 and thus equipped textile machines and yarn feeding devices.

Known thread brakes are highly prone to contamination, as od during use fluff and fluff or adhering to the threads residues of oil, paraffin od. Like. At the thread contact or braking surfaces accumulate. It is therefore known to rotatably arrange the brake elements on a bearing pin ( DE 35 04 739 A1 ) or the bearing pin, the brake elements and the usual, intended for adjusting the braking force biasing mechanism to a freely rotatably mounted in the holder assembly as a whole ( DE 197 20 795 A1 ). The rotatable mounting of the brake elements and / or the entire assembly serves the purpose of using the tangential forces exerted on the brake elements during running threads to cause the brake elements in a rotational movement and thereby cause a constant self-cleaning of the brake elements, especially if the walls preferably are provided with sufficiently large openings.

There are further known thread brakes whose brake elements are thus coupled to a vibration generating device ( DE 41 04 663 C1 ), that one the Rotational movement of the brake elements promoting force arises. From an economic point of view, however, such ancillary equipment is unacceptable to machines that consume or process a large number of filaments because they require tremendous design effort.

Apart from that, it has been found that lint and fluff stick to the brake elements provided with helical compression springs in particular despite the application of the measures described above. This can even od the desired braking force in the operation of a circular knitting machine. Like. Change or at least a reproducible adjustment of the braking force are difficult, which has frequent cleaning and therefore absenteeism of the machine result. To avoid this disadvantage, protective caps are known ( DE 41 12 898 A1 ), which are attached to the biasing mechanism and cover the helical compression springs. However, such caps not only increase the design effort, but also hinder access to the brake elements and their self-cleaning. With great effort also known thread brakes are connected ( DE 36 29 928 C2 ), in which the braking force is established or released with gas pressure.

The problems described can not be with the help of thread brakes of the type described above ( DE 913 148 C ), which are provided for adjusting the braking force with acting on the brake elements, spoke or membrane-like springs.

Furthermore, it is known ( DE 43 01 507 C2 . 295 21 428 U1 ) to adjust the braking force by means of permanent magnets instead of helical compression springs. The advantage of a reduced contamination of the biasing mechanisms here is the disadvantage that the biasing force of the brake elements and thus the force exerted on the thread braking force can only be changed by a high expenditure of time associated replacement of magnetic inserts and only in relatively large steps, while in conventional Yarn brakes provided springs allow a continuous adjustment of the braking force. The thread brakes used in practice therefore contain at least in circular knitting machines mostly biasing mechanisms, which are provided with open, no protective covers having springs, so that they must be cleaned in spite of the existing in principle tendency for self-cleaning in relatively short time intervals, resulting in a thread processing or consuming machine with a plurality of thread guides, z. B. a circular knitting machine with 96 or more systems, consuming cleaning work with appropriate machine downtime required.

Prior to this prior art, the problem underlying the invention in the provision of a yarn brake, which not only reduces the risk of contamination, but also satisfied in terms of design, by having a conventional spring mechanism for adjusting the braking force.

To solve this problem, the characterizing features of claims 1, 15 and 16 serve.

The invention has the advantage that the provided with a conventional spring, for adjusting the braking force certain biasing mechanism is not assigned to the brake elements bearing bearing portion, but mounted in a mounting bracket portion of a bearing pin. This makes it possible to accommodate the spring in a setting and protection body, which serves on the one hand for mounting the bearing pin on the holder and for adjusting the braking force and on the other hand largely covers the spring to the outside. In contrast, the braking elements are only under the action of a mounted on the bearing portion of the bearing pin pressure element, which can be provided as the brake elements themselves with smooth and only slightly prone to contamination surfaces.

Further advantageous features of the invention will become apparent from the dependent claims.

• Fig. 1 schematisch eine Seitenansicht einer Fadenliefervorrichtung mit einer Fadenbremse;
• Fig. 2 eine schematische und perspektivische Darstellung einer erfindungsgemäßen Fadenbremse;
• Fig. 3 und 4 je einen vergrößerten Längsschnitt durch die Fadenbremse nach Fig. 2 in je einem Zustand mit kleiner bzw. großer Bremskraft; und
• Fig. 5 einen der Fig. 3 entsprechenden Längsschnitt in einem nochmals vergrößerten Maßstab durch ein zweites Ausführungsbeispiel einer erfindungsgemäßen Fadenbremse in einem Zustand mit kleiner Bremskraft.

The invention will be explained in more detail below in connection with the accompanying drawings of exemplary embodiments. Show it:

• Fig. 1 schematically a side view of a yarn feeding device with a yarn brake;
• Fig. 2 a schematic and perspective view of a yarn brake according to the invention;
• 3 and 4 depending on an enlarged longitudinal section through the yarn brake after Fig. 2 in each case a state with small or large braking force; and
• Fig. 5 one of the Fig. 3 corresponding longitudinal section in a further enlarged scale by a second embodiment of a yarn brake according to the invention in a state with a small braking force.

In the Fig. 1 shown yarn feeding device comprises a carrier 1, the one with one end to a mounting rail 2 of a thread processing or thread-consuming textile machine, z. B. a circular knitting machine, is detachably fastened. On the underside of the carrier 1, a conventional storage or delivery drum 3 is arranged, which is rotatably mounted about a rotation axis 4 and fixedly connected to a rotatably mounted in the carrier 1 shaft 5 for this purpose. At one over the top of the carrier 1 protruding part of the shaft 5, at least one pulley 6 is rotatably mounted, the od of a drive, not shown, by means of a belt. The like. Driven and z. B. by means of a manually switchable clutch 6a rotatably connected to the shaft 5, thereby driving the storage or delivery drum 3.

At the free end of the carrier 1, a yarn brake 7 and arranged above this yarn eyelet 8 are attached. On the underside of the carrier 1 is arranged between the yarn brake 7 and the delivery drum 3 thread inlet guide element 9, z. As an eyelet provided while on the guide element 9 diametrically opposite side of the delivery drum 3 two attached to the underside of the carrier 1 thread outlet guide elements 10 and 11 are provided, which may consist of open or closed eyelets like the guide element 9. A thread 12 is from a supply spool, not shown, through the eyelet 8, the yarn brake 7 and the guide element 9 obliquely from above and substantially tangentially to the thread support surface led the delivery drum 3, wound on this in at least one, preferably several turns and finally unwound substantially tangentially and od through the two guide elements 10 and 11 a processing point of a knitting machine. The like. Not shown. Feeler 14 and 15, which are also mounted on the carrier 1, can serve in the usual way for monitoring the thread 12.

Thread delivery devices of this type are generally known to the person skilled in the art (eg DE 197 20 795 A1 ) and therefore need not be explained in detail.

Details of a first embodiment of the yarn brake according to the invention emerge Fig. 2 to 4 , Thereafter, the yarn brake 7, a holding element 16 in the form of an elbow od. Like. On, in a manner not shown on the carrier 1 to Fig. 1 od. Like. Can be attached. The holding element 16 carries a holder 17 with a cylindrical receptacle 18 which is provided with an internal thread 19. In the receptacle 18 in the embodiment of a hollow cylindrical or sleeve-shaped adjustment and protection body 20 is arranged, which is provided on its jacket with an external thread 21 which fits into the internal thread 19 of the holder 17. The adjustment and protection body 20 can therefore be screwed into the receptacle 18 and in this by back and forth turning axially, ie parallel to a longitudinal axis 22 of the bracket 17 back and forth.

In an inner, coaxial with the longitudinal axis 22 and outwards, ie in 3 and 4 left open cavity 23 of the adjustment and protection body 20 is a mounting portion 24 of a generally provided with the reference numeral 25 bearing pin arranged. The mounting portion 24 has an outer cross section which is smaller than the inner cross section of the cavity 23, and is located at one in 3 and 4 right, from the adjustment and protection body 20 outstanding side with a bearing portion 26 of the bearing pin 25 coaxially connected. In order to allow a largely tilt-free relative movement between the bearing pin 25 and the adjustment and protection body 20 parallel to the longitudinal axis 22, on the one hand has the Adjustment and protection body 20 on a bearing portion 26 facing in 3 and 4 right side an end wall 27 which has a coaxial bearing opening for the mounting portion 24, the inner diameter is only slightly larger than the outer diameter of the mounting portion 24 and thereby forms an annular circumferential, radially inwardly projecting shoulder. On the other hand, the mounting portion 24 at a distance from the bearing portion 26, in 3 and 4 left side a radially outwardly extending, preferably annular projection 28 which is provided with an outer cross-section which substantially corresponds to the inner cross section of the cavity 23, which preferably has the same cross section in the direction of the longitudinal axis 22. The mounting portion 24 is therefore mounted by means of the end wall or shoulder 27 and the projection 28 in the direction of the longitudinal axis 22 slidably in the adjustment and protection body 20. The projection 28 is formed in the embodiment as an integrally formed on the mounting portion 24 bead.

The mounting portion 24 and with it the whole bearing pin 25 are biased by a trained in the embodiment as a helical compression spring spring 29 in the direction of the longitudinal axis 22 and in the direction opposite to the bearing portion 26 side. The spring 29 is to coaxially drawn on the mounting portion 24, disposed in the remaining between this and the wall of the adjustment and protection body 20 part of the cavity 23 and with its ends between the projection 28 and the shoulder 27 or another shoulder of the Adjusting and protecting body 20 supported that they the bearing pin 25 in 3 and 4 tried to press to the left. The biasing force depends on the axial position of the adjustment and protection body 20 or on whether it is relatively deeply screwed into the receptacle 18 ( Fig. 3 ), which corresponds to a low biasing force, or is relatively far removed from the receptacle 18 ( Fig. 4 ), which results in a large preload force. For reproducible adjustment of the biasing force, a scale cooperating with a marking on the holder 17 can be provided on the outer jacket of the adjustment and protection body 20 On the preferably cylindrical bearing portion 26 which connects axially to the mounting portion 24 of the bearing pin 25, a preferably cylindrical bearing sleeve 31 is mounted in the embodiment, preferably made of a wear-resistant, a low friction material having such. As ceramic or a suitable plastic. The bearing sleeve 31 has an inner diameter which is slightly larger than the outer diameter of the bearing portion 26. In addition, the bracket 17 is expediently provided on a side facing the bearing portion 26 with a preferably cylindrical bearing ring 32 for the bearing sleeve 31, whose inner diameter is slightly larger than the outer diameter of the bearing sleeve 31. In this case, the bearing sleeve 31 is preferably arranged easily rotatable by a suitable clearance of a few tenths of a millimeter both on the bearing portion 26 and in the bearing ring 32. In the axial direction, the bearing sleeve 31 may also be arranged movably on the bearing section 26. Moreover, it preferably extends only to a protruding into the receptacle 18 of the holder 17 shoulder 17a, which also serves as a stop for the adjustment and protection body 20 in its maximum screwed into the receptacle 18 position.

On an outside of the bracket 17, ie in 3 and 4 To the right of this lying part of the projected by the bearing portion 26 bearing sleeve 31, a first brake element 33 and a second brake element 34 of the yarn brake according to the invention are mounted. The two brake elements 33, 34 have a substantially circular outer cross-section and are provided in their center with a respective hub 35, 36, which is preferably rotatably and axially displaceably mounted on the bearing sleeve 31 with little play. In this case, the hub 35 of the first, the bracket 17 facing the brake member 33 has an axially inner sliding surface 37, which lays in the mounted state of the yarn brake 7 to an end face of the bearing ring 32. In contrast, the hub 36 of the second brake member 34 is disposed at an axial distance from the hub 35 and with an axially outwardly, ie in 3 and 4 provided to the right-facing sliding surface 38 to which a pressing element 39 lays in the mounted state. In the exemplary embodiment, this pressing element 39 is a component which, on the one hand, increases the cross section of the bearing section 26 and on the other hand designed as a closure cap, which is attached to the remote from the mounting portion 24 end of the bearing portion 26 and preferably by a grub screw 40 od. Like. Solder is connected to this. This makes it possible to introduce the bearing pin 25 from the side of the post 17 forth only through the receptacle 18 and possibly the screwed in this setting and protection body 20 and the bearing ring 32 into the yarn brake, then from the opposite side, the bearing sleeve 31 and the brake elements 33, 34 to assemble and finally to attach the pressure element 39 on a protruding from the bearing sleeve 31 part of the bearing portion 26.

As a result of the described bias of the bearing pin 25 by the spring 29 in 3 and 4 to the left, the pressing member 39 is also biased to the left, so that it lays with a frontal sliding surface against the sliding surface 38 of the hub 36 of the second brake element 34 and this therefore with a force that depends on the axial adjustment of the adjustment and protection body 20 , axially against the first brake element 33 presses, which in turn rests with its sliding surface 37 on the bearing ring 32 of the bracket 17. The braking force exerted by the brake elements 33, 34 on the guided between them, in 3 and 4 schematically indicated thread 12 is exercised, it can by turning the adjustment and protection body 20 and its axial displacement caused thereby z. B. in the off 3 and 4 apparent limits are set.

During operation of a textile machine consuming or processing the thread 12, the thread 12 exerts a torque on the brake elements 33, 34. Depending on the diameters of the brake elements 33 and 34, the outer diameter of the bearing sleeve 31, the sizes of the sliding surfaces 37 and 38 and the sizes and diameters of the interacting with these surfaces on the bearing ring 32 and the pressure element 39 also the brake elements 33, 34 in turns offset to effect a self-cleaning in a conventional manner. A particular advantage of the invention results from the fact that the brake elements 33 and 34, the holder 17 with the bearing ring 32 and the pressure element 39 all can be provided with smooth surfaces that are not prone to fouling by lint, dust od. Like., As in particular Fig. 2 shows, and that also the size of the cooperating friction surfaces and the size of the gap remaining between the individual parts can be optimized in such a way that the ingress of lint and dust. Like. Into the interior of the yarn brake 7 is largely prevented. This is true even if, during operation, only one of the two brake elements 33, 34 alone should turn around the bearing sleeve 31 or together with it about the bearing section 26 of the bearing pin 25, which is usually not rotating.

A particularly significant advantage of the yarn brake described is, finally, that the spring 29 used to adjust the braking force outside the range of the brake elements 33, 34 and is almost completely covered by the adjustment and protection body 20 and the projection 28 to the outside. As a result, penetration of dust and dirt into the spaces between the individual turns of the spring 29 is extremely unlikely, so that the braking force once set remains unchanged over a long service life. In addition, the braking force can be adjusted easily reproducible. Finally, access to the brake elements 33, 34 is in no way hindered, which also promotes a possible self-cleaning.

The embodiment according to Fig. 5 is different from that Fig. 2 to 4 essentially only in that the bearing sleeve 31 has been omitted and another bearing pin 42 is provided. The same parts are therefore provided with the same reference numerals.

In contrast to Fig. 2 to 4 For example, the bearing pin 42 has a mounting section 43 which is arranged in the adjustment and protection body 20 and has a smaller outer diameter than a bearing section 44 of the bearing pin 42 projecting from the mounting 17 and expediently mounted in the bearing ring 32. In addition, the hubs 35, 36 of the brake elements 33, 34 are directly and preferably rotatably mounted on the bearing portion 44, wherein with regard to the optimization of the cooperating sliding or friction surfaces and the smooth axial displacement of the brake elements 33, 34 the same as in the embodiment according to Fig. 2 to 4 applies.

In the embodiment according to Fig. 5 is the particular to rest on the second brake element 34, the cross-section of the bearing portion 44 enlarging, a pressing member 45 forming member formed on the remote from the mounting portion 43 end of the bearing portion 44 and with this z. B. made in one piece. In contrast, at the opposite end of the bearing pin 42 for supporting the spring 29 and the slide bearing of the mounting portion 43 in the adjustment and protection body 20 certain projection 46 is formed as a releasably attached to the free end of the mounting portion 43 cap. The attachment of this cap takes place for example by a formed in the mounting portion 43 annular groove 47 and a latching in this, from the cap radially inwardly projecting annular bead 48. The assembly is therefore carried out in this embodiment from the right, by the first bearing pin 42 through the hubs 35th and 36, the bearing ring 32 and the adjustment and protection body 20 inserted, then inserted from the left, the spring 29 and finally the cap 46 is pressed onto the mounting portion 43.

Otherwise, the training and the function of the embodiment according to Fig. 5 those of the embodiment according to Fig. 2 to 4 , Again, the indenting element 45, the bearing pin 42, the adjustment and protection body 20, the spring 29 and the projection 46 form a specific for adjusting the braking force of the yarn brake biasing mechanism.

The invention is not limited to the described embodiments, which can be modified in many ways. For example, the bearing sleeve 31 could be firmly connected to the mounting portion 26 or fixed to the bracket 17. In addition, the brake elements 33, 34 could rotate on the bearing sleeve Be arranged 31 or the mounting portion 44, if it can be waived self-cleaning or should. Furthermore, the bearing pin could in particular in the case of Fig. 5 be formed in two parts and have a subsequently fixedly connected to the mounting portion 43 bearing portion 44, wherein other than the illustrated cross-sectional shapes are possible. Further, it would be possible to arrange the adjustment and protection body 20 axially displaceable, but non-rotatably in the receptacle 18 of the holder 17 and assign him, for example, a locking screw for fixing a desired axial position. Also, the spring 29 could be formed differently than shown. Furthermore, it is clear that the yarn brake 7 according to the invention contrary Fig. 1 can also be applied independently of a yarn feeding device and, for example, by means of the holding member 16 can be attached directly to a textile machine. Finally, it should be understood that the various features may be applied in combinations other than those illustrated and described.

Claims (16)

1. Thread brake with a holding means (17), a bearing pin (25, 42), which has an axis (22), an assembly section (24, 43) disposed in the holding means (17) and a bearing section (26, 44) located in axial direction next to said assembly section and projecting out of the holding means (17), a first brake element (33) disposed to be axially displaceable on the bearing section (26. 44) and intended for abutment against the holding means (17), and a second brake element (34) disposed to be axially displaceable on the bearing section (26, 44) and intended for abutment against the first brake element (33), and a pretensioning mechanism, which is intended for adjustment of the braking force and which has a spring (29) and a tension element (39, 45) attached to the bearing section (26, 44), characterised in that the assembly section (24, 43) is disposed to be axially displaceable in the holding means (17), the spring (29) axially pretensions the assembly section (24, 43) and the pretensioning mechanism has an adjusting and protecting member (20), which is disposed to be axially displaceable in the holding means (17) and houses the assembly section (24, 43) and the spring (29).
2. Thread brake according to Claim 1, characterised in that the adjusting and protecting member (20) is configured as a sleeve, which on a side facing the bearing section (26, 44) has an end wall (27), which has the assembly section (24, 43) projecting through it.
3. Thread brake according to Claim 2, characterised in that the end wall has a bearing opening with an inside cross-section, which corresponds essentially to the outside cross-section of the assembly section (24, 43).
4. Thread brake according to Claim 3, characterised in that the tension element (39, 45) is configured as a structural part, which increases the cross-section of the bearing section (26, 44) and is intended for abutment against the second brake element (34).
5. Thread brake according to one of Claims 1 to 4, characterised in that the two brake elements (33, 34) are disposed directly on the bearing section (26, 44).
6. Thread brake according to Claim 5, characterised in that the tension element (45) is moulded onto an end of the bearing section (44) axially remote from the assembly section (43).
7. Thread brake according to one of Claims 1 to 4, characterised in that the two brake elements (33, 34) are disposed on a bearing bush (31), which has the bearing section (26) projecting through it.
8. Thread brake according to Claim 8 [sic], characterised in that the tension element (39) is configured as a sealing cap, which is detachably fastened to an end of the bearing section (26) axially remote from the assembly section (24).
9. Thread brake according to one of Claims 1 to 8, characterised in that the assembly section (24, 43) has a radial projection (28, 46) on an end axially remote from the bearing section (26, 44), and the spring (29) is a helical pressure spring, which is tightened onto the assembly section (24, 43) and which is supported between the projection (28, 46) and a shoulder (27), which is provided on a side of the adjusting and protecting member (20) axially remote from the projection (28, 46).
10. Thread brake according to Claim 9, characterised in that the projection (28, 46) is configured in a ring shape and is provided with an outside cross-section, which essentially corresponds to the inside cross-section of a cavity (23) of the adjusting and protecting member (20) housing the assembly section (24, 43).
11. Thread brake according to Claim 9 or 10, characterised in that the projection (28) is formed by a bead moulded onto the assembly section (24).
12. Thread brake according to Claim 9 or 10, characterised in that the projection (46) is formed by a sealing cap (46) detachably connected to the assembly section (43).
13. Thread brake according to one of Claims 7 to 12, characterised in that on a side facing the bearing section (26), the holding means (17) has a bearing ring (32) intended for mounting the bearing bush (31) in an axially displaceable and rotatable manner.
14. Thread brake according to one of Claims 1 to 13, characterised in that the holding means (17) has a cylindrical seat (18) provided with an internal thread (19) and the adjusting and protecting member (20) is configured as a sleeve with an external thread (21) fitting into the internal thread (19).
15. Textile machine, in particular a circular knitting machine, with at least one thread brake (7), characterised in that the thread brake (7) is configured according to at least one of Claims 1 to 14.
16. Thread feed device with at least one thread brake (7) for a textile machine, in particular a circular knitting machine, characterised in that the thread brake (7) is configured according to at least one of Claims 1 to 14.

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