EP2256238B2 - Thread trapper device for a spindle of a spinning or thread machine - Google Patents

Description

The invention relates to a thread clamping device for a spindle of a spinning or twisting machine with a receptacle for attaching the thread clamping device to the spindle, with two mutually movable clamping elements for clamping a thread, with at least one loading element for closing the clamping elements with a loading force, and at least one Relief element for generating a load force opposing the relieving force, wherein the relief element is movable in the thread clamping device under centrifugal force with rotating spindle and wherein the clamping elements can be opened by the unloading force.

A thread clamping device of this type is by the WO 2007/131562 A1 State of the art. The loading element which causes the clamping of the thread is formed in the known thread clamping device by a spring. In the thread clamping device a plurality of relief elements are arranged in the form of balls, which are radially movable and are guided in half-shell-like guides. The guides for the balls are designed so that the clamping elements for the thread open and close during a radial movement of the balls. Upon rotation of the spindle in the operating state, the balls experience a centrifugal force increasing with the spindle speed. There is a limit speed at which the release force generated by the balls corresponds to the loading force of the spring. When this limit speed is exceeded, the thread clamping device opens. When braking the spindle falls below the limit speed, the centrifugal force of the balls is less than the loading force of the spring, so that the thread clamping device closes. Opening and closing of the clamping elements of the thread clamping device happens at one and the same speed. A similar thread clamping device is already out of the DE 196 28 826 A1 known.

The WO 2007065703 A2 relates to a thread clamping device for underwinding threads on spindles of a ring spinning or ring twisting machine, wherein between a clamping ring and a radially projecting collar on the spindle an axial, between a defined by the system to the clamping ring clamping position and an open position slidable clamping sleeve is provided. The clamping sleeve is assigned for the axial movement of an actuating device which cooperate with radially extending means on the clamping sleeve. The clamping sleeve are assigned elements for fixing their position at least in the clamping position. The actuating elements and / or the radially projecting means are held on the clamping sleeve radially to each spindle axis elastically to each other and are provided in both relative directions of movement with radially effective ramps. Magnets or spring push buttons are used to fix the clamping sleeve and thus to clamp the thread.

From the WO 2007/065703 A2 the opening and closing of the clamping elements takes place at different spindle speeds. A change of a cop sitting on the spindle, the so-called doff process, is facilitated if the thread underwinding can be done at low spindle speed and if after restarting the spinning or twisting machine, the thread remains fixed up to the highest possible spindle speed in the thread clamping device , This is done with the thread clamping device according to the WO 2007/065703 A2 realized. The opening of the clamping elements in the acceleration phase of the spindle takes place at a high speed, the closing of the clamping elements in the deceleration phase of the spindle, however, at a low speed. This behavior of the thread clamping device is achieved in that magnets are provided as loading elements. The magnets load the movable clamping elements by their attraction, thereby causing the clamping of the thread. Since the attraction of the magnets greatly reduced with increasing distance of the clamping elements, a very high unloading force, ie a high spindle speed is required to open the thread clamping device.

Since the attraction of the magnets reduces with increasing nip, the clamping force, the thicker the thread to be clamped is reduced. Especially with thicker threads, however, a stronger clamping force in the thread clamping device is required due to a higher tensile strength of the thread. In addition, magnets are expensive components, especially if they must have a high magnetic force as in the present case and at the same time must be insensitive to vibration.

The invention has for its object to provide an improved thread clamping device.

The problem is solved according to claim 1.

Characterized that at a defined and kept constant spindle speed, the relief element can exert different levels of relief forces, depending on which position it is in a thread clamping device can create that opens at a first spindle speed and at a second, different from the first spindle speed closes. Due to the variable unloading forces no magnets in the thread clamping device are required. The loading force of the at least one loading element can be higher in the opened state of the clamping elements than in the closed state of the clamping elements. This makes it possible to achieve the advantage that the clamping force of a thicker thread is greater than the clamping force of a thinner thread. During a Kopswechselvorganges so thick yarns or threads can be held securely in the thread clamping device. Nevertheless, all load elements by very inexpensive spring elements be formed.

In an advantageous embodiment it is provided that a closed state of the clamping elements and a second position of a relief element is associated with an open state of the clamping elements a first position of a relief element, wherein the relief element in the first position with closed clamping elements a low unloading force and in the second position open clamping elements high discharge force can be generated. This comparison is made at a predetermined and kept constant speed of the spindle. This embodiment has the advantage that the clamping elements open in the acceleration phase of the spindle only at a high spindle speed and close again in the deceleration phase at a low spindle speed. The opening and closing of the thread clamping device happens when the unloading force and the loading force are in equilibrium. The fact that the relief element can take two positions in the thread clamping device, in which it generates different relief forces, there are two limit speeds, in which the unloading force and load force are in equilibrium. Advantageously, when an upper limit rotational speed of the spindle is exceeded, a relief element for opening the clamping elements from the first position to the second position movable, and falls below a lower limit than the lower limit speed is a relief element for closing the clamping elements of the second position back into the first position movable. Since only a low unloading force at a predefined spindle speed can be generated by the relief element in the first position, a higher spindle speed is required conversely until the unloading force is sufficient to release the loading force and bring the clamping elements into the open state. In the deceleration phase of the spindle, the relief element is in the second position and generates accordingly - at the same speed - a higher unloading force. The spindle speed can therefore be lowered to the lower limit speed without closing the clamping elements. Only when falling below the lower limit speed, the unloading force falls below the loading force, and leads to a closing of the clamping elements.

To avoid imbalances on the spindle, it is advantageous to arrange a plurality of relief elements on the circumference of the thread clamping device. Preferably, a relief element is formed by a substantially radially movable centrifugal force body. A centrifugal body is advantageously formed by a ball.

The centrifugal body are assigned at least two contact surfaces. A first contact surface is associated with the first position of the centrifugal force body and a second contact surface with the second position of the centrifugal force body. The contact surfaces are at a different radius, which is defined by the distance of the contact surface to the center line of the receptacle for attaching the thread clamping device to the spindle. Since the centrifugal body moves radially from the first position to the second position and thereby opens the clamping elements, it is advantageous to arrange the contact surface assigned to the first position to a smaller radius than the contact surface assigned to the second position.

According to the invention, a tangent applied at the contact point between a centrifugal force body and a contact surface, seen in the axial section of the thread clamping device, has an angle to the center line of the receptacle, and a tangent is present at a contact surface lying on a small radius, which has a small angle to the center line of the receptacle, and that at a lying on a large radius abutment surface a tangent is present, which has a large angle to the center line of the receptacle. The angle between the tangent and the center line determines the size of the unloading force with the same centrifugal force of the relief element. With this configuration, a very simple thread clamping device can be created in which different relief forces can be generated by a relief element at a definable spindle speed. In coordination with the mass of the centrifugal body, the upper and lower limit speed can be adapted in a very simple manner by the geometry of the contact surfaces to the requirements. On expensive magnets can be dispensed with. An additional assembly step for the attachment of the magnets in the thread clamping device can be omitted. An inventive thread clamping device can thus be produced in small quantities with little effort.

It is advantageous if the tangent applied at the point of contact intersects the midline. Particularly preferably, the tangent lies in the axial section plane of the receptacle. This results in a particularly good conversion of the centrifugal force generated by the centrifugal force in one of the loading force opposing unloading force. The low angle is between 0 ° and 20 ° and is particularly preferably in the range of 5 ° to 10 °. The large angle is advantageously between 60 ° and 80 ° and is particularly preferably in the range of 60 ° to 75 °.

In a further embodiment, it may be advantageous for a contact surface lying on a small radius to have a region which, viewed in axial section, encloses a small angle with the center line of the receptacle. A contact surface lying on a large radius can have a region which, viewed in axial section, encloses a large angle with the center line of the receptacle. Areas of the contact surfaces that run straight in axial section leave make it very easy. Also, the unloading force generated by the centrifugal body is substantially constant over the rectilinear region of the contact surface, so that the influence of manufacturing tolerances on the upper and lower limit speed can be reduced. In an area extending in a straight line contact surface, the angle between the contact surface and center line corresponds exactly to the angle between the center line and a tangent applied to the contact surface of the centrifugal body tangent.

In order to ensure a smooth movement of the centrifugal body in the radial direction, it may be advantageous that between the lying on a small radius contact surface and lying on a large radius contact surface, a contact surface is present whose angle to the center line increases steadily with increasing radius ,

It may be advantageous that a contact surface for a centrifugal body is arranged on a deformable by centrifugal force component of the thread clamping device. The centrifugal body and the deformable by centrifugal force component have a contact point in which a tangent can be applied. This embodiment has the advantage that the angle of the tangent to the central axis of the recording changes during the acceleration phase of the spindle. At low spindle speeds, the angle of the tangent to the center line is very small, so that a high upper limit speed is reached by the additional component, in which open the clamping elements. The deformable by centrifugal force component is preferably formed by a ring. The center of the ring is preferably on the center line of the receptacle. The ring may advantageously consist of a rubber-elastic material. The ring is preferably arranged so that it does not hinder the movement of the centrifugal body when closing the clamping elements.

Further advantages and features of the invention will become apparent from the following description of some embodiments.

• Figur 1 eine teilweise geschnittene Axialansicht auf eine vergrößert dargestellte Spindel, mit einer geschlossenen Fadenklemmeinrichtung,
• Figur 2 die gleiche Spindel aus Figur 1 mit geöffneter Fadenklemmeinrichtung,
• Figur 3 den mit III gekennzeichneten Bereich der Figur 1 in vergrößerter Darstellung,
• Figuren 4 bis 8 Ansichten ähnlich Figur 3 bei anders ausgestalteten Fadenklemmeinrichtungen,
• Figur 9 eine Ansicht ähnlich Figur 3 auf eine abgewandelte Ausgestaltung einer Fadenklemmeinrichtung,
• Figur 10 eine entlang der Schnittfläche X-X der Figur 9 geschnittene Ansicht.

Show it:

• FIG. 1 a partially sectioned axial view of an enlarged illustrated spindle, with a closed thread clamping device,
• FIG. 2 the same spindle FIG. 1 with opened thread clamping device,
• FIG. 3 the area marked III in FIG. 1 in an enlarged view,
• FIGS. 4 to 8 Similar views FIG. 3 in differently configured thread clamping devices,
• FIG. 9 a view similar FIG. 3 to a modified embodiment of a thread clamping device,
• FIG. 10 one along the section XX of the FIG. 9 cut view.

In FIG. 1 a spindle 1 of a spinning or twisting machine is shown. The spindle 1 consists of a rotating upper part 2 and a non-rotating bearing housing 3, which is fixedly mounted on a spindle bank, not shown. The upper part 2 has a co-rotating shaft 4 which is mounted in the bearing housing 3 in a neck bearing 5 and a footrest, not shown. The upper part 2 contains a whorl 6, via which it can be driven by a belt 7.

Above the whorl 6 a thread clamping device 8 is arranged. The thread clamping device 8 is mounted with a receptacle 9 on the spindle upper part 2. The thread clamping device 8 is preferably releasably attached to the upper part 2 in order to be easily replaceable in the event of a defect. The upper part 2 can receive above the thread clamping device 8, a spool sleeve, not shown, on which the yarn produced is wound up into a coil. The Aufwindevorgang is carried out in a known manner by means of a raised and lowered ring rail, which extends over a plurality of juxtaposed in the machine spindles 1. Each spindle 1 is associated with a spinning ring, also not shown, on which a rotor rotates in a known manner, which gives the thread a rotation during operation and guides it to the spool.

The thread clamping device 8 consists of a sleeve-shaped base body 10 which contains the receptacle 9 for the spindle 1. On the main body 10, an axially displaceable sleeve 11 is arranged. On the main body 10 and on the sleeve 11, a respective clamping element 12 and 13 is arranged. The clamping elements 12 and 13 include clamping surfaces 14 and 15, which may form a gap 16 for clamping a thread. The thread to be clamped is also called "underwind thread". The opened gap 16 between the clamping elements 12 and 13 is in FIG. 2 recognizable. The thread clamping device 8 includes a loading element 17 in the form of a spring. The loading element 17 generates a loading force that presses the clamping element 13 on the sleeve 11 against the clamping element 12 on the base body 10, so that an underwinding thread between the clamping surfaces 14 and 15 can be clamped.

The movement of the sleeve 11 during opening and closing of the clamping elements 12, 13 is ensured by two guides 41 and 42. Thus, the sleeve 11 is guided precisely on the base body 10, a first guide in the region of the clamping element 13 is arranged. A second guide 42 is spaced as far as possible from the first guide 41. The guide 41 and the guide 42 are arranged so that the loading element 17 and the relief elements 18 seen in axial section between the two guides 41, 42 are located. To minimize unwanted imbalances on the thread clamping device 8, the spring 17 is guided and centered by the base body 10.

The thread clamping device 8 also includes a plurality of relief elements 18 for generating a load force opposing the load force. In the FIGS. 1 and 2 two relief elements 18 are shown. It can be arranged evenly distributed on the circumference of the thread clamping device 8 several relief elements 18. The relief element 18 is formed by a substantially radially movable centrifugal force body 19 in the form of a sphere. The ball is preferably made of steel.

In the in FIG. 1 illustrated closed state of the clamping elements 12, 13, the relief element 18 is in a first position. The centrifugal body 19 is guided in a guide 20 in the main body 10. The centrifugal body 19 is associated with a first bearing surface 21. The contact surface 21 is arranged on the sleeve 11. Under centrifugal force with rotating spindle 1, the ball 19 applies to the contact surface 21 at. The contact surface 21 includes a small angle A with the center line 23 of the receptacle 9 a. By the angle A, the ball 19 generates a force in the axial direction of the center line 23 on the sleeve 11, which is opposite to the loading force of the spring 17. When the spindle speed exceeds an upper limit speed, the unloading force exerted by the ball 19 exceeds the loading force of the spring 17 so that the sleeve 11 moves toward the whorl 6. As a result of the movement of the sleeve 11, the clamping elements 12, 13 open. At the same time, the ball 19 in the guide 20 moves radially outwards into a second position over a larger radius.

The state of the thread clamping device 8 with open clamping elements 12, 13 is in FIG. 2 recognizable. The centrifugal body 19 are in the second position and between the clamping surfaces 14 and 15, the gap 16 is opened. In this position, the centrifugal body 19 is associated with a second bearing surface 22 on the sleeve 11, which has an angle B to the center line 23 of the receptacle 9. The angle B is greater than the angle A. Apart from the fact that the centrifugal force generated by the ball 19 at a given spindle speed in this second position is slightly larger, since the distance of the ball to the rotation axis 23 is slightly larger, the unloading force is the Ball 19 on the sleeve 11 due to the larger angle B much larger than in the first position. Now, if the spindle speed is reduced again, the thread clamping device 8 closes when it falls below the upper limit speed at which the thread clamping device 8 had opened, not yet again. Only when falling below a lower limit speed, the relief force decreases so far that the discharge force falls below the loading force of the spring 17 and the sleeve 11 is pressed by the spring 17 back up. The loading element 17 closes the clamping elements 12, 13 and the ball 19 moves back to the first position, see FIG. 1 ,

In FIG. 3 is again the area around the ball 19 shown as a relief element 18 enlarged. It can be seen that the ball 19 rests against the guide 20 of the main body 10 and on the contact surface 21 of the sleeve 11. Due to the angle A of the contact surface 21 to the center line 23 is formed in the contact point 24 between the centrifugal body 19 and the contact surface 21 of the clamping force opposing unloading force. The contact surface 21 has a region extending in a straight line in axial section. The angle A of the contact surface 21 is thus identical to that of a tangent applied to the ball 19 at the contact point 24. The second contact surface 22, against which the ball 19 rests when the thread clamping device is open, lies on a larger radius than the first contact surface 21. The second contact surface 22 has a large angle B to the center line 23. The angle B is substantially greater than the angle A. This angle difference is achieved that the thread clamping device 8 opens at a high spindle speed, and closes only at a much lower spindle speed again.

To clarify the sequence when operating a spindle 1 with a thread clamping device 8 according to the invention is described once again chronologically. During the spinning or twisting operation with operating speed, which is for example 20,000 1 / min, the thread clamping device 8 is opened. The gap 16 is empty. The thread is wound on the sleeve, which is located on the upper part 2 of the spindle 1. Before a cop-change process, in which the full bobbin or the full cop is exchanged for an empty sleeve, the ring rail is moved with the ring in a position that the thread inserts into the gap 16. In this so-called underwinding of the thread, the speed of the spindle 1 is reduced. If the spindle speed falls below the lower limit, the thread clamping device 8 closes and the underwinding thread is clamped between the clamping elements 12 and 13. Then the spindle is stopped and the full cop is pulled up from the upper part 2. The yarn end coming from the stretching or delivery unit remains clamped when pulling off the full cop in the thread clamping device 8 and the thread is separated between cop and thread clamping device 8. After placing an empty sleeve on the upper part 2, the machine is started again. During the acceleration of the spindle 1, the ring rail is already raised again to a position so that the thread is wound onto the seated on the upper part 2 sleeve. If the spindle speed exceeds an upper limit, the thread clamping device 8 opens again and the thread end clamped in the gap 16 is ejected. In order to ensure safe and reliable operation during a cop switching operation, it is advantageous if the lower limit speed is very low, for example of the order of about 1,000 to 2,000 l / min. When inserting the underwind thread in the gap 16, it is important that the thread is safe for a safe in the gap 16 to be clamped reliably, but on the other hand, the thread may not wrap the main body 10 of the thread clamping device more than 360 °, so that the thread end later again easily detached from the clamping elements 12 and 13. An insertion of the underwinding thread in the gap 16 can be realized more precisely and easily if the spindle speed is as low as possible. Therefore, it is important that the thread clamping device 8 closes at the lowest possible lower limit speed. In contrast, it is very advantageous in the acceleration phase of the spindle when the upper limit speed at which the thread clamping device 8 opens again, at the highest possible spindle speed, for example, in the order of 10,000 1 / min, is. The clamped between the clamping elements 12 and 13 end of the underwinding thread is thereby kept safe in the thread clamping device 8 until enough turns are wound on the empty tube. Malfunctions and yarn breakage during cop change can be greatly reduced.

For further optimization of the thread clamping device 8, the design of the contact surfaces 21 and 22 can be varied. In the FIGS. 4 to 8 some advantageous variants are shown.

In the variant in FIG. 4 is between the contact surface 21 and the contact surface 22, a region 25 is present, the angle to the center line 23 between the angle A and the angle B is located. By the contact surface 25 of the transition of the ball 19 is improved by the contact surface 21 on the contact surface 22. A further improvement of the guidance of the ball 19 can be achieved if between the lying on a small radius contact surface 21 and lying on a large radius contact surface 22, a contact surface 26 is present, the angle with the center line 23 increases steadily with increasing radius. Such a rounded contact surface 26 is in FIG. 5 shown.

In FIG. 6 an advantageous variant is shown, in which the contact surface 21 and the contact surface 22 are already curved. It can thereby achieve a particularly gentle transition of the ball 19. In the left part of the FIG. 6 the position of the ball 19 is shown with closed thread clamping device. The right part of the FIG. 6 shows the ball 19 with open thread clamping device 8. For the relief force caused by the ball 19 is at a curved contact surface 21, the tangent applied at the contact point 24 27 and its angle A to the center line 23 prevail. Even if the ball 19 is in the open thread clamping device 8 on the contact surface 22, in turn, the angle B of a tangent 28 in the contact point between the ball 19 and bearing surface 22 is relevant.

Since the bearing surfaces 21 and 22 in the FIGS. 3 to 5 have rectilinear areas there fall the tangents 27 and 28 with the surface of the support surfaces 21, 22 together. The angle A is preferably in the range between 5 ° and 10 °, particularly preferably about 6 °. The angle B is advantageously in the range of 60 ° to 75 °, and in particular about 65 °.

In FIG. 7 a variant is shown in which the contact surface 21 has a slight elevation. The tangent 27 at the contact point 24 thereby has a very small angle A to the center line 23. This makes it possible to achieve a relatively high upper limit speed for opening the thread clamping device.

In FIG. 8 The sleeve 11 of the thread clamping device 8 contains a component 29 that can be deformed by the action of centrifugal force. The contact surface 21, against which the centrifugal force element 19 rests when the thread clamping device 8 is closed, is arranged on the deformable component 29. The tangent 27 applied in the contact point 24 in turn has a small angle A to the center line 23. The deformable component 29 is advantageously formed by a ring 30. The center of the ring 30 lies on the center line 23 of the receptacle. The ring 30 is made of a rubber-elastic material. The ring 30 causes the thread clamping device 8 opens only at a high upper limit speed. The spindle speed must become so high that the ring 30 widens due to the action of centrifugal force and thereby enables the ball 19 to change its position. In the deceleration phase of the spindle 1, the deformable component 29 is not a hindrance to the moving from the second to the first position ball 19. By a corresponding arrangement of a ring 30 may in the embodiment according to FIG. 8 even the angle A of the tangent 27 to be reduced to a negative value, so that at the beginning of the acceleration phase of the centrifugal body 19, the clamping force of the clamping elements 12, 13 amplified and thereby the clamping action of the thread clamping device 8, especially with thick threads, further improved. With increasing spindle speed and increasing expansion of the ring 30, the angle A increases steadily until the ball 19 finally pushes over the ring 30 over.

In the in the FIGS. 1 to 8 illustrated embodiments, the stroke that the sleeve 11 executes during its axial movement to open and close the gap 16, smaller than the diameter of the balls 19. If a larger stroke of the sleeve 11 is desired or smaller balls 19 are used, so is a special adaptation of the guide 20 of the balls 19 in the main body 10 of the thread clamping device 8 advantageous.

In the FIGS. 9 and 10 an embodiment of a thread clamping device 8 is shown, in which the stroke of the sleeve 11 is greater than the diameter of the balls 19. As in the embodiments of Figures 1 to 8 11 two contact surfaces 21 and 22 are provided on the sleeve, which have a different angle A and B to the center line 23 of the spindle 1 have. The contact surfaces 21 and 22 are arranged on a radially inwardly projecting web 51. The web 51 protrudes into a recess 52 of the base body 10. The web 51 is arranged so that the ball 19 is centrally supported. The guide 20 for the ball 19 in the main body 10 is formed so that the ball 19 is guided by two segment-shaped guide surfaces 53 and in the radial direction from the illustrated first position to a second position similar to the illustration in FIG FIG. 2 can move. The guide surfaces 53 are formed by cutouts of peripheral surfaces of a cylinder. As in FIG. 10 clearly visible, the guide 20 and the contact surfaces 21, 22 arranged symmetrically to the ball center. The ball 19 is thereby guided very precisely, so that they do not jam in their radial movement.

Of course, also in the FIGS. 3 to 8 illustrated embodiments of the contact surfaces 21, 22 in one embodiment according to the FIGS. 9 and 10 deploy.

Claims (12)

1. Yarn nipping device for a spindle (1) of a spinning or twisting machine comprising a receptacle (9) for mounting the yarn nipping device (8) on the spindle (1), comprising two nipping elements (12, 13) movable in opposite directions to one another for nipping a yarn, also comprising at least one loading element (17) for closing the nipping elements by means of a loading force, also comprising at least one load-relieving element (18) for generating a relieving force which acts in opposite direction to the direction of the loading force, wherein the at least one load-relieving element (18) is movable in the yarn nipping device under centrifugal force when the spindle (1) is rotating, wherein the nipping elements (12, 13) can be opened by means of the load-relieving force, wherein at least two positions are assigned to at least one load-relieving element (18) in the yarn nipping device (8) and at a definable spindle speed different load-relieving forces are generable by the load-relieving element (18) depending on said position, wherein a load-relieving element (18) is formed by an essentially radially movable centrifugal force body (19), wherein at least two supporting surfaces (21, 22) are assigned to the centrifugal force body (19), wherein the supporting surfaces (21, 22) lie on different radii, which are formed by the distance of the supporting surface (21; 22) to the centre line (23) of the receptacle (9) for mounting the yarn nipping device (8) on the spindle (1), wherein a tangent (27; 28) drawn in a contact point (24) between a centrifugal force body (19) and a supporting surface (21; 22) - as seen in axial section of the yarn nipping device (8) - forms an angle (A; B) in relation to the centre line (23) of the receptacle (9), wherein a tangent (27) is formed on a supporting surface (21) lying on a lesser radius, said tangent (27) forming a small angle (A) in relation to the centre line (23) of the receptacle (9) and wherein a tangent (28) is formed on a supporting surface (22) lying on a larger radius, which tangent (28) forms a large angle (B) in relation to the centre line (23) of the receptacle (8) characterized in that the small angle (A) is between 0° and 20°.
2. Yarn nipping device according to claim 1, wherein a closed state of the nipping elements (12, 13) is assigned to a first position of a load-relieving element (18), and an opened state of the nipping elements (12, 13) is assigned to a second position of a load-relieving element (18), whereby the load-relieving element (18) can generate a low level of load-relieving force in the first position when the nipping elements (12, 13) are closed, and can generate a high level of load-relieving force in the second position when the nipping elements (12, 13) are open.
3. Yarn nipping device according to claim 1 or 2, wherein the loading force of the at least one loading element (17) is greater in the open state of the nipping elements (12, 13) than in the closed state of the nipping elements (12, 13).
4. Yarn nipping device according to claim 3, wherein all loading elements (17) take the form of spring elements.
5. Yarn nipping device according to any one of the claims 1 to 4, wherein when an upper threshold speed of the spindle (1) is exceeded, a load-relieving element (18) for opening the nipping elements (12, 13) is movable from the first position into the second position, and wherein when the threshold speed falls below a low threshold lower than the upper threshold speed, a load-relieving element (18) for closing the nipping elements (12, 13) is movable from the second position into the first position.
6. Yarn nipping device according to any one of the claims 1 to 5, wherein a number of load-relieving elements (18) are arranged on the circumference of the yarn nipping device (8).
7. Yarn nipping device according to any one of the claims 1 to 6, wherein the centrifugal force body being preferably formed by a ball (19).
8. Yarn nipping device according to claim 1, wherein a supporting surface (21) lying on a lesser radius comprises an area which, as seen in axial section, encompasses a small angle (A) in relation to the centre line (23) of the receptacle (9).
9. Yarn nipping device according to claim 1 or 8, wherein a supporting surface (22) lying on a larger radius comprises an area which, as seen in axial section, forms a large angle (B) with the centre line (23) of the receptacle (9).
10. Yarn nipping device according to any one of the claims 8 or 9, wherein between the supporting surface (21) lying on a lesser radius and the supporting surface (22) lying on a larger radius, a supporting surface 26 exists whose angle in relation to the centre line (23) of the receptacle (9) increases consistently with increasing radius.
11. Yarn nipping device according to any one of the claims 1, 8, 9 or 10, wherein a supporting surface (21) for a centrifugal force body (19) is assigned to a component (29) of the yarn nipping device (8), said component (29) being deformable by centrifugal force action.
12. Yarn nipping device according to claim 11, wherein the component (29) which is deformable by centrifugal force action takes the form of a ring (30) the ring (30) is being preferably made of a flexible rubber material.

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