THREAD CLAMPING DEVICE

Description

[0001] The invention relates to a thread clamping device for a spindle of a spinning or twisting machine for releasably fixing a thread in a clamping gap, with a first clamping unit with an inner sleeve which can be arranged coaxially to the spindle and a thread separator which can be fixed in the axial direction on the inner sleeve, wherein the first clamping unit can be fixed in an axially positioned manner on an upper part of the spindle, and a second clamping unit with a clamping element which can be adjusted axially relative to the first clamping unit between a clamping position which closes the clamping gap between the thread separator and the clamping element and an open position which releases the clamping gap.

[0002] Thread clamping devices of the type mentioned above are known in a variety of designs from the prior art, for example, from DE 10 2011 076 744 A1. Such thread clamping devices can be used to secure the so-called wrapping thread when replacing a full thread spool on a spinning or twisting machine.

[0003] For this purpose, the thread clamping devices generally have a first and a second clamping unit mounted on a rotatable upper part of a spinning or twisting spindle. The first clamping unit has, for example, an inner sleeve mounted in a torsionally fixed manner on the rotatable upper part of the spinning or twisting spindle and a thread separator resting at one end on the inner sleeve, with the inner sleeve being fixed at the other end to the upper part of the spinning or twisting spindle for axial position securing. The second clamping element, for example an outer sleeve arranged coaxially to the inner sleeve, is mounted so as to be movable in the axial direction relative to the rotatable upper part of the spinning or twisting spindle and the first clamping unit and is held, for example by a spring, in a clamping position closing the clamping gap between the thread separator and the second clamping element up to a certain speed of the spinning or twisting spindle.

[0004] The second clamping element is designed such that, in the clamping position, it secures the thread in the clamping gap without the application of centrifugal forces caused by rotation of the upper part of the spinning or twisting spindle. Under the influence of centrifugal forces, however, the second clamping element is axially displaced toward the open position, in which a thread secured in the clamping gap is released.

[0005] In known thread clamping devices, the connecting area of the upper part of the spinning or twisting spindle is partially knurled to ensure a torsion-proof connection to the inner sleeve of the first clamping unit. During assembly, the knurled section cuts into the inner sleeve, creating a circumferentially positive connection between the inner sleeve and the upper part of the spinning or twisting spindle. However, the partially knurled design of the upper part of the spinning or twisting spindle places high demands on the manufacturing of the spinning or twisting spindle. If the edges of the knurled section are not sufficiently sharp, for example, they will not cut into the plastic of the inner sleeve in the specified manner when the inner sleeve is assembled to the upper part of the spinning or twisting spindle.This results in a material displacement process instead, in which the inner sleeve is pushed radially outward, causing the outer diameter of the inner sleeve to increase in sections. This can lead to undesirable friction between the inner sleeve and the clamping element, which can be axially displaced relative to the inner sleeve, which can lead to a blockage and thus to failure of the thread clamping device.

[0006] Alternatively, it is already known from DE 10 2011 076 744 A1 to form the inside of the inner sleeve with a toothed annular surface for engagement with a corresponding contour of the spindle upper part. This solution also places high demands on the manufacturing of both the inner sleeve and the spindle upper part. If the toothing is inaccurately designed, material displacement can also occur on the inner sleeve side, which pushes the inner sleeve radially outward.

[0007] The document DE 10 2013 020 470 A1 discloses a thread clamping device with the preamble features of claim 1.

[0008] Based on this, the invention is based on the object of providing a thread clamping device which enables a twist-proof connection of the inner sleeve to the spindle of the spinning or twisting machine in a simple and reliable manner.

[0009] The invention solves the problem by a thread clamping device having the features of claim 1. Advantageous developments of the invention are specified in the dependent claims.

[0010] The thread clamping device according to the present invention comprises a first and second

[0011] clamping unit. The first clamping unit comprises an inner sleeve which can be arranged coaxially to the spindle and a thread separator which can be fastened axially to the inner sleeve, wherein the first clamping unit can be fastened axially to an upper part of the spindle. The second clamping unit is equipped with a clamping element which can be adjusted axially relative to the first clamping unit between a clamping position which closes the clamping gap between the thread separator and the clamping element and an open position which releases the clamping gap. The second clamping unit can have a conventional design known from the prior art. For example, the clamping element of the second clamping unit can be designed as a one-part or multi-part outer sleeve which is mounted by the inner sleeve so that it can move relative to the inner sleeve. For this purpose, the inner sleeve and the outer sleeve or the clamping element can be mounted on their inner or outer sides.The outer side has corresponding bearing and displacement means that are operatively connected or connected to one another. Examples of bearing means that may be mentioned are projections and recesses that can be brought into engagement with one another and are designed accordingly on the inner sleeve and the clamping element in order to be able to effect a guided relative movement of the clamping element to the inner sleeve. The displacement means can preferably be formed by a conventional centrifugal force unit that has several centrifugal force elements that are mounted between the inner sleeve and the clamping element in such a way that the clamping element can be moved relative to the inner sleeve depending on the speed of the spindle for the corresponding opening and closing of the clamping gap.

[0012] The thread separator is designed to axially position the inner sleeve on the upper part of the spindle and to torsionally connect the inner sleeve to the upper part of the spindle. The thread separator and the inner sleeve can also be connected to one another in a torsionally fixed manner. To arrange the thread clamping device on the upper part of the spindle of a spinning or twisting machine, the inner sleeve of the first clamping unit is pushed onto the upper part of the spindle. In the pushing-on direction, the axial position of the inner sleeve can preferably be determined by a corresponding design of the spindle, e.g. by a projection or shoulder against which the inner sleeve can be placed at one end. According to the invention, the thread separator, which is fixed on the spindle in the axial direction and is operatively connected to the inner sleeve at the other end, serves to axially secure the position of the inner sleeve against the direction of pushing it onto the spindle.

[0013] According to the present invention, the thread cutter, in addition to securing the axial position of the inner sleeve, also serves to connect the inner sleeve to the spindle in a rotationally fixed manner, wherein for this purpose the thread cutter can be connected at least rotationally fixed to the inner sleeve and more preferably rotationally fixed to the upper spindle part. Accordingly, in addition to axially positioning the inner sleeve on the upper spindle part at least counter to the direction of insertion of the inner sleeve, the thread cutter also serves to connect the inner sleeve to the spindle in a rotationally fixed manner, wherein the thread cutter, in its position on the upper spindle part axially positioning the inner sleeve, effects the first clamping unit and also the rotationally fixed connection to the upper spindle part.The torsion-proof connection of the thread separator to the inner sleeve in this position of the thread separator achieves a torsion-proof connection of the inner sleeve to the upper part of the spindle, so that a separate design of the spindle in the connection area with the inner sleeve for the torsion-proof connection is not necessary.

[0014] The thread clamping device thus enables a particularly simple and reliable, torsion-resistant assembly of the inner sleeve to the spindle upper part, effectively preventing deformations of the inner sleeve that could lead to malfunctions, for example, in interaction with connecting elements on the spindle upper part. The thread clamping device according to the present invention enables a particularly simple and cost-effective connection of the thread clamping device to the spindle.

[0015] The torsion-proof connection of the thread cutter to the spindle upper part can, in principle, be designed in any desired manner, for example, via positive connections, in which the anti-twist protection between the spindle upper part and the thread cutter is achieved through a specific shape. According to a preferred embodiment of the invention, the thread cutter can be pressed onto the spindle upper part.

[0016] According to this embodiment of the invention, the thread cutter is designed such that, when the thread clamping device is mounted on the spindle, it is connected to the spindle upper part via a press connection in a rotationally fixed manner. The press connection is designed such that, in addition to reliably positioning the inner sleeve in the axial direction of the spindle, at least counter to the direction of insertion of the inner sleeve, it also ensures that the inner sleeve is secured against rotation relative to the spindle. The press connection between the spindle and the thread cutter is particularly simple and cost-effective to produce.

[0017] For a torsion-proof connection of the thread cutter to the inner sleeve, in addition to the positive connection, a preferred embodiment of the invention provides for the thread cutter to be connected to the inner sleeve in a non-positive and / or non-positive manner. A non-positive connection can be created, for example, by a suitable design of the surfaces of the contactable surfaces of the thread cutter and inner sleeve, with the contact force and the friction between the surfaces ensuring reliable anti-twist protection. A non-positive connection can be achieved, for example, by adhesive bonding.

[0018] To produce the positive connection, the invention provides that the thread cutter has engagement elements that can be brought into engagement with a contact section on the inner sleeve, in particular that can be pressed into the contact section. According to this embodiment of the invention, the thread cutter is designed in the contact area with the inner sleeve such that, before or during assembly of the thread clamping device on the spindle, engagement elements on the thread cutter are impressed into the inner sleeve at defined points, thereby producing a positive connection between the inner sleeve and the thread cutter. This embodiment of the invention enables a substantially play-free, twist-proof arrangement of the inner sleeve on the spindle in a particularly reliable and simple manner.Furthermore, the design of the thread separator ensures the axial positioning of the first clamping unit on the spindle top both in and against the direction of the inner sleeve's insertion. With this design, it is entirely possible to dispense with elements on the spindle top or on the spindle itself that secure the inner sleeve in the insertion direction.

[0019] Particularly preferably, the engagement elements can be pressed into the contact section of the inner sleeve, which is made of a material deformable by the application of force, for clamping the inner sleeve to the spindle upper part. For example, selected or all of the engagement elements on the thread separator can be dimensioned such that, when the thread clamping device is mounted on the spindle, the engagement elements are impressed into the contact section of the inner sleeve, which is made of, for example, a plastic-containing material, in such a way that material displacement occurs towards the center of the inner sleeve, which results in a reduction of the inner diameter of the inner sleeve at the corresponding material displacement points, thereby creating a clamping force that clamps the inner sleeve to the spindle upper part.Preferably, the thread separator can generally be made of a metal-containing material, which allows the engagement elements, particularly in this preferred embodiment, to be impressed more reliably and easily into the contact section of the inner sleeve. Particularly preferably, the thread separator made of metal-containing material is manufactured using a sintering process, as opposed to conventional turning processes. This allows polygonal engagement elements, in particular, to be formed extremely precisely on the thread separator. The first clamping unit can thus be secured to the upper spindle part in a simple and reliable manner, both in the circumferential direction and in the axial direction, without the need for any further securing elements on the inner sleeve and / or the upper spindle part.The inner diameter of the inner sleeve is preferably selected in dependence on the outer diameter of the spindle upper part in such a way that the inner diameter of the inner sleeve enables the inner sleeve to be pushed onto the spindle upper part and the clamping effect by pressing in the engagement elements.

[0020] According to a further preferred embodiment of the invention, the contact section on the inner sleeve has coupling elements that can be brought into operative connection with the engagement elements. According to this embodiment of the invention, coupling elements adapted to the shape of the engagement elements on the thread cutter are arranged in the contact section of the inner sleeve. When the thread clamping device is mounted on the spindle, these coupling elements interact positively with the corresponding engagement elements in the circumferential direction, thus ensuring a reliable, anti-twist connection. The engagement elements and the coupling elements can particularly preferably be designed as teeth, which enable particularly reliable, anti-twist and axial positioning of the inner sleeve over the thread cutter both in the axial and circumferential directions.

[0021] According to a further embodiment of the invention, a connecting element is arranged in the area between the contact section and the thread separator, which is designed for a non-positive and / or positive-locking, torsion-proof connection with the contact section and the thread separator. According to this embodiment of the invention, the connecting element serves as an adapter element, which can be connected in an axial direction to both the thread separator and the contact section of the inner sleeve in a rotation-proof manner. The use of a connecting element thus makes it possible to connect the thread separator and the inner sleeve in a rotation-proof manner, regardless of their design in the connection area. The connecting element serves as an adapter, which connects at least the thread separator and the inner sleeve in a circumferential direction in a non-positive and / or positive-locking manner, so that a coordinated adaptation of the thread separator and the contact section can be dispensed with.

[0022] The connecting element can further preferably be designed to fix the first clamping unit to the spindle upper part axially and rotationally secure by means of clamping or press fitting. In this case, the connecting element can preferably be arranged with a press fit on the spindle upper part and / or have engagement elements as described above for generating a clamping effect with the spindle upper part by means of material displacement on the side of the thread separator and / or on the side of the contact section during assembly of the thread clamping device. Alternatively, the operative connection between the thread separator and the connecting element and / or between the contact section of the inner sleeve and the connecting element can be such that the material displacement as described above on the side of the connecting element for clamping the first clamping unit to the spindle upper part can be brought about by providing corresponding engagement elements on the thread separator and / or the contact section.The component or a corresponding component section featuring the material displacement is made of a material that can be deformed by the application of force, such as a plastic-containing material. As described above, the inner diameter is to be designed in accordance with the outer diameter of the spindle upper part so that the clamping effect or the interference fit can be created by means of the material displacement.

[0023] According to a preferred embodiment of the invention, it is provided that the connecting element is designed as an adhesive ring or toothed ring, which can ensure a non-positive and / or positive torsion-resistant connection in a particularly reliable manner, wherein the adhesive ring provides a sufficient frictional torque and the toothed ring ensures a reliable positive connection.

[0024] Furthermore, in contrast to the prior art, the thread separator can preferably be produced from a metal-containing material by means of a sintering process, whereby in particular the polygonal shape can be formed more precisely.

[0025] Embodiments of the invention are explained below with reference to the drawings. In the drawings: Fig. 1 is a schematic representation of an exploded view of a thread clamping device according to one embodiment; Fig. 2 is a perspective schematic view of another embodiment of an inner sleeve of a thread clamping device; Fig. 3 is a perspective schematic view of a thread separator of the thread clamping device of Fig. 1 ; Fig. 4 is a perspective schematic representation of a further embodiment of a thread separator and Fig. 5 is a perspective schematic view of a further embodiment of a thread separator.

[0026] The Figure 1 The thread clamping device 1 shown for clamping a thread on an upper part of a spindle (not shown here), in particular on a spinning or twisting machine (also not shown here), comprises an inner sleeve 3a of a first clamping unit 2 which can be arranged in a rotationally fixed manner relative to the upper part of the spindle and which, in addition to the inner sleeve 3a, also has a thread separator 4a which can be pressed onto the upper part of the spindle and which fixes the thread clamping device 1 in the axial direction against its direction of insertion onto the upper part of the spindle.

[0027] For the torsion-proof connection of the inner sleeve 3a with the spindle upper part, the thread separator 4a, which can be pressed torsionally onto the spindle upper part, is provided with coaxially circumferentially arranged engagement elements 9 in the form of teeth 15 in the contact area with the inner sleeve 3a (cf. Figure 3 ).

[0028] When the thread clamping device 1 is mounted on the spindle upper part, the teeth 15 press into the contact section 8a on the inner sleeve 3a at the end face and cause such a material displacement of the contact section 8a toward the inner sleeve center that the inner sleeve is clamped axially and non-rotatably to the spindle upper part, thus ensuring a non-rotatable arrangement of the inner sleeve 3a on the spindle upper part. Alternatively or additionally, the thread separator 4a can be arranged in a non-rotatable and axially fixed manner via a press fit on the spindle upper part.

[0029] Arranged coaxially to the inner sleeve 3a is a clamping element 6 which is displaceable in the axial direction relative to the inner sleeve 3a. This clamping element forms an outer sleeve which can be pushed onto the inner sleeve 3a and can be displaced in a known manner along the longitudinal axis 11 relative to the inner sleeve 3a and the thread separator 4a. The mutually facing surfaces of the thread separator 4a and the clamping element 6 form a clamping gap 7 of the thread clamping device 1, in which the thread can be clamped on the spindle. According to this exemplary embodiment, the axially displaceable clamping element 6 is mounted on the inner sleeve 3a by means of a helical compression spring 12 in such a way that, in the rest position of the spindle, it is arranged in the clamping position in which the clamping element 6 is in contact with the thread separator 4a.For the automated displacement of the clamping element 6 in the direction of the opening position releasing the thread, the thread clamping device 1 comprises, in a known manner, a centrifugal force unit (not shown here), the centrifugal force mechanism of which comprises a plurality of centrifugal force elements which space the axially displaceable clamping element 6 from the thread separator 4a as soon as the spindle rotates at a certain minimum speed, whereby the clamping gap 7 is opened and a thread arranged in the clamping gap 7 is released.

[0030] In Figure 2 A further embodiment of an inner sleeve 3b is shown in a simplified schematic form, which is used for the torsion-proof connection with the Figure 3 illustrated thread separator 4a has in the contact section 8b a coaxially circumferential toothing 14 consisting of a plurality of coupling elements 10. The design of the toothing 14 on the inner sleeve 3b is adapted to the design of the toothing 14 of the Figure 3illustrated thread separator 4a, so that a reliable, twist-proof connection between the thread separator 4a and the inner sleeve 3b is ensured in the mounting position of the thread clamping device 1 on the spindle upper part.

[0031] Figure 4 shows a further embodiment of a thread separator 4b, in which the coupling elements 9 are formed by spherical caps 16, which are pressed into the contact section 8a of the inner sleeve 3a during assembly of the first clamping unit 2 and thus ensure a torsion-proof connection via the thread separator 4b arranged torsion-proof on the upper part of the spindle.

[0032] Figure 5shows a further embodiment of a thread separator 4c, in which the engagement elements 9 for the rotationally secure connection to the inner sleeve 3a are formed by a plurality of webs 17 arranged one behind the other in the circumferential direction, which webs form a polygonally shaped contact surface which establishes a positively acting connection in the circumferential direction with the contact section 8a of the inner sleeve 3a. List of reference symbols

[0033] 1 Thread clamping device 2 First clamping unit 3a, 3b Inner sleeve 4a, 4b, 4c Thread separator 5 Second clamping unit 6 Clamping element 7 Clamping gap 8a, 8b Contact section 9 Engagement element 10 Coupling element 11 Longitudinal axis 12 Helical compression spring 13 Sealing element 14 Toothing 15 Tooth 16 Spherical caps 17 Webs

Claims

1. Thread clamping device (1) for a spindle of a spinning or twisting machine for releasably fixing a thread in a clamping gap (7), comprising - a first clamping unit (2) having an inner sleeve (3a, 3b) which can be arranged coaxially to the spindle, and a thread separator (4a, 4b, 4c) which can be fixed to the inner sleeve (3a, 3b) in the axial direction, the first clamping unit (2) being fixable in an axially positioned manner to an upper part of the spindle, and - a second clamping unit (5) having a clamping element (6) which is axially adjustable relative to the first clamping unit (2) between a clamping position closing the clamping gap (7) between the thread separator (4a, 4b, 4c) and the clamping element (6) and an opening position exposing the clamping gap (7), the thread separator (4a, 4b, 4c) being designed for axially positioning and fixing the inner sleeve (3a, 3b) to the spindle upper part and for connecting the inner sleeve (3a, 3b) to the spindle upper part for conjoint twisting, and the thread separator (4a, 4b, 4c) and the inner sleeve (3a, 3b) being connectable to one another for conjoint twisting, characterized in that the thread separator (4a, 4b, 4c) has engagement elements (9) which can be brought into engagement with a contact portion (8a, 8b) on the inner sleeve (3a, 3b), or a connecting element is arranged in the region between a contact portion (8a, 8b) on the inner sleeve (3a, 3b) and the thread separator (4a, 4b, 4c), which connecting element is force-fittingly and / or form-fittingly connected to the contact portion (8a, 8b) and the thread separator (4a, 4b, 4c) for conjoint twisting.

2. Thread clamping device (1) according to claim 1, characterized in that the thread separator (4a, 4b, 4c) is made of a metal-containing material by means of a sintering process.

3. Thread clamping device (1) according to claim 1 or 2, characterized in that the connecting element can be arranged at least with a press fit on the spindle upper part or has engagement elements (9) for producing a clamping effect with the spindle upper part by means of material displacement on the side of the thread separator (4a, 4b, 4c) and / or on the side of the contact portion (8a, 8b) during assembly of the thread clamping device (1), the thread separator (4a, 4b, 4c) or the contact portion (8a, 8b) being made of a material deformable by the application of force.

4. Thread clamping device (1) according to claim 1 or 2, characterized in that the connecting element can be arranged at least with a press fit on the spindle upper part or the thread separator (4a, 4b, 4c) or the contact portion (8a, 8b) has engagement elements (9) for producing a clamping effect with the spindle upper part by means of material displacement on the side of the connecting element during assembly of the thread clamping device (1), the connecting element being made of a material deformable by the application of force for clamping the first clamping unit (2) to the spindle upper part.

5. Thread clamping device (1) according to any of claims 1 to 3, characterized in that the engagement elements (9) can be pressed into the contact portion (8a) made of a deformable material for clamping the inner sleeve (3a) to the spindle upper part.

6. Thread clamping device (1) according to one or more of the preceding claims, characterized in that the contact portion (8a, 8b) has coupling elements (10) which can be brought into operative connection with the engagement elements (9).

7. Thread clamping device (1) according to 6, characterized in that the engagement elements (9) and in particular the coupling elements (10) are designed as teeth (14).

8. Thread clamping device (1) according to one or more of the preceding claims, characterized in that the connecting element is designed as an adhesive ring or toothed ring.