EP2336408A2 - Yarn tension device for a double-strand twisting spindle - Google Patents

Abstract

The thread brake (14) comprises a brake element (29), which is stored in the area of a hollow axle (5) of a spindle between an upper brake surface (28) and a lower brake surface (30). The thread brake is pneumatically detachable for inserting a thread (3,4). An upper piston (27) receives the upper brake surface, and is guided with a play (S) inside a housing of the thread brake.

Description

The invention relates to a yarn brake for a double twisting spindle according to the preamble of claim 1.

Thread brakes for double twisting spindles have long been known in various embodiments and described in detail in numerous patents in part.

Such thread brakes are used in particular in double-twisting processes and ensure that the thread receives a certain bias during the twisting process.

By the DE 31 39 236 C2 For example, a double-twisting spindle with a thread brake is known, which is designed as a brake cartridge.

In such designed as brake cartridges yarn brakes are based on two telescopically sliding, apart by a spring element cylinder with their spherical ends on braking surfaces, which are arranged in the region of a thread inlet opening or a Fadenauslassöffnung a brake housing and thereby clamp the continuous thread.

A disadvantage of such brake cartridges, however, is that the bias of the yarn during the twisting process is determined only by the spring force of the spring element of the brake cartridge, and, at least during the twisting process, can not be corrected. Furthermore, for example by the DE 33 36 715 C2 or the US 7,000,865 B1 Braking devices for double twisting spindles known, each having a ball which rests in a brake housing on a braking surface.

In this type of braking device, the braking force acting on the continuous thread is dependent on the weight of the ball, that is, the bias of the thread can be adjusted to a certain extent on the diameter of the ball.

In such trained braking devices, however, the achievable braking force is relatively low.

In order to be able to realize higher bias voltages, it has therefore already been proposed to arrange several such ball brakes in succession.

The DE 197 55 825 A1 describes a double twisting spindle for twisting natural silk, the yarn brake has a total of seven successively arranged Bremskugeleinrichtungen.

Such braking devices not only require a relatively large installation space, but are also with respect to the threading of a new thread extremely disadvantageous.

By the DE-GM 81 10 891 also thread brakes for double twisting spindles are known in which an upper piston which is acted upon by a spring element and which is equipped with a first, upper braking surface acts on a brake ball, which in turn to a second lower braking surface is pressed.

By turning a spring element abutment, the pretension of the spring element and thus the contact pressure of the brake ball can be set defined on the braking surfaces.

In this known yarn brake also the brake ball can be lifted pneumatically, which greatly facilitates the threading of a new thread in the yarn brake.

A disadvantage of this type of yarn brake, however, is that the spring-loaded piston, which has the upper braking surface slides almost without play in an axial guidance of the yarn brake housing.

That is, the upper braking surface can not escape laterally, which leads to Fadenanomalitäten, such as knots, thick spots, dust particles, etc. lead to strong thread tension increases up to thread breakages.

Based on the aforementioned prior art, the present invention seeks to develop a yarn brake for a double twisting spindle, which is designed so that they avoid thread tension increases that could lead to a yarn breakage, as far as possible.

This object is achieved by a yarn brake having the features described in claim 1.

Advantageous embodiments of the invention are the subject of the dependent claims.

The inventive construction of the thread brake, wherein the upper brake surface receiving upper piston is formed and guided with play within a housing of the thread brake that he can dodge if necessary in a position in which its central longitudinal axis with the central longitudinal axis of the housing an angle has the advantage that the upper piston automatically responds to thread abnormalities.

That is, at the occurrence of Fadenanomalitäten at least the upper brake surface integrated in the upper piston immediately deviates slightly laterally.

In this way, unwanted increases in thread tension, especially yarn breaks, reliably prevented already in approach.

As described in claim 2, it is provided in an advantageous embodiment that the angle, which is set at the occurrence of Fadenanomalitäten between the central longitudinal axis of the upper piston and the central longitudinal axis of the housing of the yarn brake, up to 10 °.

Such a relatively small tilt angle on the one hand minimizes the constructive effort in the area of the thread brake, but nevertheless ensures that the occurrence of high thread tensions when overflowing the upper braking surface is prevented by, for example, knots, thick spots or dust buffs.

According to claims 3 and 4, the escape of the upper piston is made possible in the event of yarn abnormalities in that the upper piston is provided with guide lugs, which allow a certain lateral displacement of the piston.

The upper piston has, for example, a disc-shaped lower guide lug whose diameter is below the inner diameter of the housing in the working area of the guide lug (Anspr.3).

Furthermore, the upper piston has a preferably circular upper guide surface whose inner diameter is above the outer diameter of the hollow axis of the double-wire spindle (Anspr.4).

Such a design ensures on the one hand a clean guidance of the upper piston in the housing of the thread brake during the normal "twisting operation and on the other hand, if necessary, an immediate, safe evasion of the upper braking surface.

As described in claim 5, at least the disc-shaped lower guide lug in an advantageous embodiment, a convex curved, circumferential guide surface.

Such a convexly curved guide surface on the one hand favors the tiltability of the piston and on the other hand reliably prevents the piston from becoming jammed in the housing. Overall, a convex curved, circumferential guide surface has a positive effect on the function of the thread brake if necessary.

According to claim 6 is provided in an advantageous embodiment that the upper piston is acted upon by two spring elements arranged one behind the other, each having different spring characteristics and their bias, as defined in claim 7, defined adjustable via a rotatably mounted abutment device.

The abutment device has wendelartig arranged detent positions, which are easily ingested by appropriate rotation of the abutment device in the housing of the yarn brake.

As set forth in claim 8, the lower braking surface to which the braking element is pressed, integrated in a lower piston, which is acted upon by a spring element, positioned in a working position and pneumatically for threading a new thread is lowered into a threading position.

Such a design facilitates the threading of a new thread, especially in combination with one of the devices described in claims 9 - 11 and 12, respectively.

As described in claim 9, it is provided in a first advantageous embodiment that in the region of the brake element a limited axially movable support element is arranged. This support element is positioned during the twisting operation by the lower piston in a rest position and slides when lowering the lower piston in its threading position in an intermediate position.

The support member also has, as set forth in claim 10, for guiding the braking element on an inclined plane.

When lowering the lower piston and thus when retracting the support element in its intermediate position, the brake element slides on the inclined plane automatically in an off-center position.

The off-center position is defined by a receiving pocket, which, as set forth in claim 11, is embedded in the lower piston.

That is, the braking member has when threading a new thread with neither the upper braking surface, still with the lower braking surface contact, but is, spaced from the braking surfaces and outside the threadline of new threads, in a receiving pocket of the lower piston.

As can be seen without difficulty, is ensured by such training in a safe way that the sucking new threads through the yarn brake is in any way hindered.

In an alternative embodiment, provision is made for a support element to be installed on the housing in the region of the brake element. On this stationary support element sets when lowering the lower piston in its threading the brake element.

The support element is designed so that even with the brake element resting between the support element and brake element sufficient space is available, so that it is ensured even in this embodiment that new threads can be easily threaded.

In an advantageous embodiment it is also provided that both the braking element formed as a brake ball, and the braking surfaces are made of a material that is very resistant to abrasion.

That is, the brake ball and / or the braking surfaces may, for example, as set forth in claim 13, made of hardened steel, which is a relatively inexpensive construction, or the brake ball and / or the braking surfaces, as described in claim 14, from an oxide ceramic Be made of material.

Such oxide-ceramic materials are known to have a high hardness and are correspondingly very wear-resistant.

The invention will be explained in more detail with reference to an embodiment shown in the drawings.

Fig.1

eine Doppeldrahtzwirnspindel mit einer im Bereich der Hohlachse der Spindel angeordneten, erfindungsgemäßen Fadenbremse,

Fig.2A

die in Fig.1 angedeutete, erfindungsgemäße Fadenbremse in einem größeren Maßstab sowie im Schnitt, wobei der untere Kolben in seiner Arbeitsstellung positioniert ist,

Fig.2B

die in Fig.2A dargestellte Fadenbremse, der untere Kolben und damit das Bremselement sind hier allerdings in einer Einfädelstellung positioniert,

Fig.3A

ein Ausschnitt auf eine weitere Ausführungsform einer Fadenbremse zu einem Zeitpunkt, an dem kein Zwirnprozess läuft,

Fig.3B

den in der Fig. 3A dargestellten Ausschnitt der Fadenbremse, während des Zwirnprozesses beim Durchlaufen eines "normalen" Fadens,

Fig.3C

den in der Fig. 3A dargestellten Ausschnitt der Fadenbremse, während des Zwirnprozesses beim Durchlaufen einer Fadenanomalität,

Fig.4

im Schnitt, eine detaillierte Darstellung der drehbar gelagerten Widerlagereinrichtung der Fadenbremse, die zum Einstellen der Vorspannung der auf den oberen Kolben wirkenden Federelemente dient,

Fig.5

im Schnitt eine perspektivische Ansicht auf eine zum Einfädeln eines neuen Fadens geöffnete Fadenbremse gemäß der in den Figuren 3a - 3c dargestellten Ausführungsform.

It shows:

Fig.1

a double-twisting spindle with a thread brake according to the invention arranged in the region of the hollow axis of the spindle,

2A

in the Fig.1 indicated, yarn brake according to the invention in a larger scale and in section, wherein the lower piston is positioned in its working position,

2B

in the 2A shown thread brake, the lower piston and thus the brake element are here, however, positioned in a threading position,

3A

a detail of another embodiment of a thread brake at a time when no twisting process is running,

3B

in the Fig. 3A illustrated section of the thread brake, during the twisting process when passing through a "normal" thread,

Figure 3C

in the Fig. 3A illustrated section of the thread brake, during the twisting process when passing through a Fadenanomalität,

Figure 4

in section, a detailed representation of the rotatably mounted abutment device of the thread brake, which serves to adjust the bias of the force acting on the upper piston spring elements,

Figure 5

in section, a perspective view of an open for threading a new thread yarn brake according to the in the FIGS. 3a-3c illustrated embodiment.

The Fig.1 shows schematically, partially in section, a total designated by the reference numeral 1 double twisting spindle. With such a double-twisting spindle 1, one or more threads are given rotation.

This rotation pitch serves to increase the quality of the thread (s), for example, in terms of tear strength and so that the better processability in subsequent processes, such as weaving, knitting, tufting and the like.

• Wie im Ausführungsbeispiel der Fig.1 dargestellt, werden beispielsweise von einer Vorlagespule 2, die in einem stationären Schutztopf 9 gelagert ist, Fäden 3 und 4 abgewickelt und von oben in die Hohlachse 5 der Doppeldrahtzwirnspindel 1 eingezogen.

The actual double wire process runs approximately as follows:

• As in the embodiment of Fig.1 are shown, for example, from a supply spool 2, which is mounted in a stationary protective pot 9, unwound threads 3 and 4 and pulled from above into the hollow shaft 5 of the double-twisting spindle 1.

When passing through the hollow shaft 5, the threads 3 and 4 are twisted by a rotatably mounted spindle part 6, which is disposed below the protective pot 9, L-shaped deflected and get, preferably on a functioning as a balloon restrictor sheath 7, in balloon form upward sliding, to a stationary balloon yarn guide 8, to then be wound on a winding device 10, as now verzwirnter thread 15 to a coil 11.

As in Fig. 1 shown, the spindle part 6 in the exemplary embodiment at the end a whorl 12, which is acted upon by a tangential belt 13 frictionally in the sense of rotation.

In order to allow the twisting process to proceed smoothly, a thread brake 14 according to the invention is also installed in the region of the hollow shaft 5 of the double-twisting spindle 1, which pre-brakes the continuous threads 3, 4.

Such preliminary braking is necessary in order to be able to form a thread reserve in the region of a storage part of the spindle part 6, which is necessary for a trouble-free twisting process.

The FIGS. 2A and 2 B show a first advantageous embodiment of the yarn brake 14 according to the invention in a larger scale and in detail.

The Fig. 2A shows the yarn brake 14 with a positioned in working position A braking element 29, while the Fig. 2B the yarn brake 14 in threading position E shows.

As in the FIGS. 2A and 2 B shown, the thread brake 14 has a tubular housing 16, which is provided both on its upper side, as well as on its underside each with a (unspecified) screw internal thread.

A cover 17, which on the one hand forms a guide for the hollow axle 5 and, on the other hand, an abutment for a first spring element 18 arranged inside the cover 17, is fastened in the housing 16 via the upper screw internal thread.

This first spring element 18 acts on a pot-shaped trained, guided on the inner wall of the housing 16 abutment element 19 of the hollow shaft 5, which in turn is equipped with a plurality of helically arranged locking positions 20.

These helically arranged detent positions 20 correspond alternately with a cam 21 arranged stationary on the inner wall of the housing 16.

As in particular from Figure 4 Seen by light, one of the helically arranged locking positions 20 can be positioned on the stationary cam 21 by appropriate rotation of the hollow shaft 5 and thus the axial position of the abutment element 19 in the housing 16 can be adjusted.

Since the axial position of the abutment member 19 presets the bias of a second and a third spring element 23, 24 can over the hollow shaft 5, the braking force of the yarn brake 14 can be set defined.

That is, in the interior of the abutment member 19, a spring element 23 is arranged, which corresponds to a sleeve 22, which in turn is guided on the inner wall of the abutment member 19.

Between the sleeve 22 and a lower guide lug 25 of an upper piston 27, the spring element 24 is also turned on. The upper piston 27 is mounted via guide lugs 25, 26 within the housing 16 of the thread brake 14, wherein the upper piston 27 is equipped both with a lower guide lug 25 whose outer diameter d, as in 3A shown under the

Inner diameter D of the housing 16 in the working range of the piston 27 is located, as well as an upper guide lug 26 has, whose inner diameter d _{1 is} greater than the outer diameter D _{1 of} the hollow shaft. 5

That is, the upper piston 27 is supported both in the region of the upper, as well as in the region of the lower guide lug with game S.

Furthermore, a ring-like insert made of a wear-resistant material, for example hardened steel or an oxide-ceramic material, is fixed on the upper piston 27 and forms an upper braking surface 28 in conjunction with a brake element 29, preferably a brake ball.

The brake ball 29, which is preferably also made of a wear-resistant material, is, acted upon by the spring force of the spring elements 23, 24 described above, also on a lower braking surface 30.

Like the upper braking surface 28, the lower braking surface 30 is preferably designed as a ring-like insert and made of hardened steel or an oxide-ceramic material.

The lower braking surface 30 is arranged in a lower piston 31, which is positioned during the twisting process by a fourth spring element 33 in its working position A and has a lower hollow shaft 32.

The lower piston 31 positioning spring element 33 is supported on an intermediate insert 34 which is fixed in the lower screw internal thread of the housing 16, and in turn receives a cover member 35 in which a selectively controllable pneumatic cylinder 36 is mounted.

As in particular from the FIGS. 3A-3C can be seen, at least the lower guide projection 25 of the upper piston 27 on a convex curved guide surface 40, which allows the upper piston 27, in particular in conjunction with the given in the region of the guide lugs 25, 26 game S, if necessary from the in 3A shown position in which the central longitudinal axis 37 of the upper piston 27 and the central longitudinal axis 38 of the housing 16 are parallel to escape into one of the working positions, in the FIGS. 3B or 3C are shown.

The Fig. 3B shows the yarn brake 14 according to the invention during the "normal" twisting process.

The introduced into the hollow shaft 5 of the double-twisting spindle 1 threads 3, 4 are acted on the one hand in the region of the upper braking surface 28 and on the other hand in the region of the lower braking surface 29 by the brake ball 29 with a predetermined braking force and thus provided with a necessary for the twisting process bias.

The threads twisted into a thread 15 leave the thread brake 14 through the lower hollow axle 32 of the lower piston 31.

As in the embodiment of Fig. 3B shown, the upper piston 27 supported by play S in the housing 16 is slightly tilted by the threads 3, 4 running over the upper braking surface 28.

That is, the braking surface 28 differs slightly laterally, so that a certain, relatively small angle α is established between the central longitudinal axis 37 of the upper piston 27 and the central longitudinal axis 38 of the housing 16, on the one hand by the thread thickness of the threads 3, 4 and on the other hand depends on the respective thread condition.

When Fadenanomalitäten occur, for example, if, as in the embodiment of Figure 3C shown, a relatively thick node 41 reaches the upper braking surface 28, the upper braking surface 28 deviates immediately by tilting the upper piston 27 from.

The thereby adjusting between the central longitudinal axis 37 of the upper piston 27 and the central longitudinal axis 38 of the housing angle α is above the angle α, which results in "normal" twisting operation.

As in Fig. 3C In addition, the upper braking surface 28 is also raised by an amount V, depending on the thickness of the node 41. The two movements of the upper piston 27 described above reliably prevent a too high thread tension from building up due to a relatively thick knot 41, which would ultimately lead to a yarn breakage.

As in the FIGS. 2b and 5 shown, the thread brake 14 for threading new threads 3, 4 also be opened.

That is, the lower piston 31 and thus the lower braking surface 30 can be lowered by appropriate actuation of the pneumatic piston 36 against the force of the spring element 33 from the working position A in the threading position E.

The brake ball 29 detaches from the upper braking surface 28 and then slides, depending on the embodiment, either, as in Fig. 2B represented, on the inclined plane 44 of the support element 2 in a receiving pocket 45 in the lower piston 31 or the brake ball 29 comes, as in Fig. 5 shown slightly spaced from the upper braking surface 28 on a support element 42a for support, which is part of the housing 16.

In both embodiments, in this so-called threading position E, the lower braking surface 30 is positioned so that upon application of a negative pressure to the output of the double twisting spindle 1 in the hollow axes 5 and 32 of the yarn brake 14, a negative pressure flow 43 sets, which is easy threading new threads 3, 4 in the thread brake 14 allows.

After threading the threads 3,4 of the pneumatic piston 36 is depressurized. The spring element 33 then pushes the lower piston 31 and thus the lower braking surface 30 in the working position A.

In this action, the brake ball 29 is again pressed against the upper braking surface 28, that is, the yarn brake 14 is back in its working position.

With regard to the spring elements 18, 23, 24, 33, it should be noted that preferably spring elements are used which have different characteristics. However, spring elements can be used which have the same characteristics.

Furthermore, the spring elements can either be used in series operation as set out in the present exemplary embodiments, or else in parallel operation.

The use of spring elements with progressive characteristics is quite conceivable.

About the grid graduation of the abutment member 19, the resulting braking force curve can also be designed to suit requirements. The resulting braking force characteristic can, for example, be linear, degressive, progressive, etc.

Claims (14)

Yarn brake for a double twisting spindle with a brake element mounted in the region of a hollow axle of a spindle between an upper and a lower braking surface, the braking force being biased by at least one spring element acting on an axially displaceably mounted upper piston into which the upper braking surface is integrated; can be predefined, and the thread brake is pneumatically releasable for the insertion of a thread,
characterized,
in that the upper piston (27) receiving the upper braking surface (28) is designed and guided with play (S) within a housing (16) of the yarn brake (14) so that it can move to a position (I) if necessary, in which its central longitudinal axis (37) forms an angle (α) with the central longitudinal axis (38) of the housing (16). Yarn brake according to claim 1, characterized in that in the position (I) between the central longitudinal axis (37) of the upper piston (27) and the central longitudinal axis (38) of the housing (16) an angle (α) adjusts, the up to 10th ° is. Yarn brake according to claim 1, characterized in that the upper piston (27) has a disc-shaped lower guide lug (25) whose diameter (d) under the inner diameter (D) of the housing (16) in the working region of the guide lug (25). Yarn brake according to claim 1, characterized in that the upper piston (27) has a circular, upper guide lug (26) whose inner diameter (d ₁ ) over the outer diameter (D ₁ ) of the hollow shaft (5) of the spindle. Yarn brake according to claim 3, characterized in that at least the lower guide lug (25) has a convexly curved, circumferential guide surface (40). Yarn brake according to Claim 1, characterized in that the upper piston (27) is acted upon by second and third spring elements (23, 24) arranged one behind the other, which have different spring characteristics. Yarn brake according to claim 6, characterized in that the bias of the spring elements (23, 24) via an abutment device (19) is adjustable, which is rotatably mounted within the housing (16) and helically arranged detent positions (20). Yarn brake according to claim 1, characterized in that the lower braking surface (30) is integrated in a lower piston (31), which during the twisting operation, by at least one spring element (33) acted upon, in a working position (A) is positioned and for threading a new thread (3, 4) is pneumatically lowered into a threading position (E). Yarn brake according to claim 1, characterized in that in the region of the braking element (29) a limited axially movable support member (42) is arranged, which is positioned during the twisting operation by the lower piston (31) in a rest position (R) and when lowering the lower piston (31) in its threading position (E) in an intermediate position (Z) slides, in which the braking element (29) is positioned off-center. Thread brake according to claim 9, characterized in that the support element (42) has an inclined plane (44), which ensures an off-center positioning of the brake element (29). Yarn brake according to claim 9, characterized in that the brake element (29) is mounted in a receiving pocket (45) of the lower piston (31) when the lower piston (31) is lowered. Yarn brake according to claim 1, characterized in that in the region of the braking element (29) a support element (42A) is installed, on which when lowering the lower piston (31) in its threading position (E), the brake element (29) sets, wherein the Support element (42A) is formed so that even when the brake element (29) resting on a new thread (3, 4) can be threaded. Yarn brake according to claim 1, characterized in that the brake element (29) designed as a brake ball and / or the braking surfaces (28, 30) consist of an abrasion-resistant material, for example of hardened steel. Yarn brake according to claim 1, characterized in that the brake ball (29) and / or the braking surfaces (28, 30) are made of an oxide ceramic material.

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