Title of Invention

OPENING CYLINDER FOR ROTOR SPINNING MACHINES

Abstract

1. Opening cylinder for rotor spinning machines, comprising a plurality of teeth which are arranged to extend in a row in a continuous spiral-shaped manner on the periphery thereof and are aligned such that their advancing tooth flanks form an acute angle in each case in the direction of rotation with a circle of the opening cylinder described by the rotational path of the tooth, characterised in that the acute angle K is at least 1° and at most 2.5° with respect to the direction of rotation of the opening cylinder (4).

Full Text

FORM 2 THE PATENT ACT 197 0 (39 of 1970) THE Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) TITLE OF INVENTION OPENING CYLINDER FOR ROTOR SPINNING MACHINES APPLICANT(S) a) Name b) Nationality c) Address SAURER GmbH & CO., KG. GERMAN Company LANDGRAFENSTRASSE 45, D-41069, MONCHENGLADBACH, GERMANY ORIGNAL 328/MUMNP/2005 PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - GRANTED 30-10-2006 Description Opening cylinder for rotor spinning machines The invention relates to an opening cylinder for rotor spinning machines according to the preamble of claim 1 and a saw tooth wire according to the preamble of claim 7. Opening cylinders of this type are used to open a presented fibre band into individual fibres. The individual fibres are then fed by the opening cylinder to the spinning rotor of the rotor spinning machine through a fibre guide channel and spun into a thread. It is important for the functioning of the opening cylinder rotating at a high speed that the individual fibres are entrained to an adequate degree by the opening cylinder and the detachment of the individual fibres from the opening cylinder, caused as a result of the centrifugal force and the vacuum prevailing at the opening of the fibre guide channel, is not impeded. DE 41 24 714 Al describes that fibre drawing takes place as long as the fibres of the presented fibre band are still held by the draw-in roller. The individual fibre is released by the opening cylinder from the fibre tuft, accelerated and conveyed onward. In order to promote the entrainment, the tooth flanks should not be too smooth, but have a certain roughness. However, in the detachment zone of the opening cylinder, this roughness is undesired and hinders the detachment of the fibres from the opening cylinder. To overcome this drawback and to improve the entrainment and detachment of the individual fibres, the opening cylinder described in DE 41 24 714 Al has openings through which air is taken in in the opening region and air is blown out in the detachment region. This opening cylinder with an air assisted function is constructionally complex and expensive. Because of the particles of dirt always present in the region of the opening cylinder, such as for example fine dust and fibre particles, there is a high risk of soiling of the openings and the impairment of functioning connected therewith. DE 195 09 743 Al discloses an opening cylinder, in which the entrainment of the individual fibres by the teeth of the opening cylinder is to be improved in that the face of the tooth flanks is enlarged by a certain formation of the tooth back. Owing to the larger face, the friction between tooth flanks and fibres is to be reinforced and therefore an entrainment of the fibres by the tooth flanks improved. The detachment of the fibres entrained after combing out from the card clothing is not impeded by the strong incline of the tooth back. In this manner a good compromise is supposed to have been reached between the effects of combing out that are desired in terms of spinning, entrainment and detachment of the fibres. Roughness, in particular a high degree of roughness, of the tooth flanks of the teeth, as addressed in DE 41 24 714 Al and DE 195 09 743 Al, leads to disadvantageous fibre damage and increased risk of soiling by the fibre abrasion. The detachment of the fibres is impeded by the roughness to an undesired extent. The object of the invention is to improve the functioning of the opening cylinder. The object is achieved with an opening cylinder with the features of claim 1 and a saw tooth wire with the features of claim 7. Advantageous configurations of the invention are the subject of the sub-claims. While, as for example can be seen from DE 195 09 743 Al, a plurality of angles is optimised in the formation of the tooth form, no importance was obviously accorded to the angle K. Generally, the angle K is about 0.5° in a row of teeth extending in a spiral-shaped manner. The small change according to the invention in the angle K leads to surprisingly clear improvement in the functioning of the opening cylinder. The configuration according to the invention of the opening cylinder brings about an improvement in the entrainment of the fibres at the combing out location, without this leading to a poorer detachment of the individual fibres from the opening cylinder in the region of the opening of the fibre guide channel, such as in an increase in the roughness serving the same purpose. The tooth flanks may be smoother in design relative to the surface roughness according to the prior art, with the result that the individual fibres are released more easily from the opening cylinder without the entrainment of the fibres at the combing out location becoming inadequate. A smoother surface of the tooth flanks advantageously counteracts fibre damage and a high occurrence of dust and fibre particles in the region of the spinning rotor. A configuration according to Fig. 3 leads to a dense distribution of the teeth on the periphery of the card clothing ring, whereby an adequately large number of tooth engagements into the fibre material provided and therefore the required opening effect is ensured. The teeth are subjected to heavy wear during the spinning operation and this reduces their effect during combing out of the presented fibre band. In order to be able to retain the required yarn quality, the tooth card clothing has to be exchanged. When using a one-piece card clothing ring according to claim 5, the exchange can be carried out particularly quickly and easily. In a configuration according to claim 6, only the saw tooth wire has to be exchanged in the. case of wear of the teeth. In a configuration according to claim 4 or claim 7, the value of the angle K can be reached or increased, in order to reach a value according to the invention, without the direction of the rows formed by the teeth having to be changed. The angular position of the advancing tooth flank of the teeth can be advantageously produced together with the punching of the tooth form by shaping or material removal. The use of an opening cylinder according to the invention at a spinning station brings about improved entrainment and detachment of the individual fibres and a reduction in the soiling and leads to an increase in the quality of the yarn produced at this spinning station. The invention will be described with the aid of an embodiment shown in the figures, in which: Fig. 1 shows a partially sectional simplified basic view of a rotor spinning device, Fig. 2 shows a part view of an enlarged schematic view of a card clothing ring equipped with teeth, Fig. 3 shows a partially sectional side view A of a portion of a row of teeth of Fig. 2, Fig. 4 shows a simplified view of a portion of a saw tooth wire in plan view. The opening apparatus 1 shown in Fig. 1 comprises an opening cylinder 4 rotating in a housing 2 in the direction of the arrow 3. Arranged upstream from the opening apparatus 1 is a feed apparatus 5, by means of which a fibre band 6 is fed to the opening cylinder 4. The feed apparatus 5 comprises a feed cylinder 8 rotating very slowly in the direction of the arrow 7 relative to the opening cylinder 4, which feed cylinder cooperates with a feed table 2 9 and, together therewith, forms a clamping location 9 for the fibre band 6. The feed cylinder 8 rotates continuously and guides the fibres of the fibre band 6 to the opening cylinder 4. The opening cylinder 4 has, on the periphery, a plurality of outwardly directed teeth 10. This can be produced, for example, by winding a saw tooth wire onto the basic body 36 of the opening cylinder 4. If the fibre material of the fibre band 6 reaches the operating region of the teeth 10, a so-called fibre tuft 19 forms, in which the fibre material is combed or the fibres thereof are parallelised. Individual fibres are continuously released from the clamping location 9 and grasped by the teeth 10 of the opening cylinder 4 owing to the continuous rotational movement of the feed roller 8 and the conveyance onward of the fibre band 6 brought about thereby. The individual fibres are entrained by the opening cylinder 4 into the opening region 11 of the fibre guide channel. 12. In the opening region 11, the individual fibres are released by the opening cylinder 4 by the cooperation of centrifugal force and a suction force provided through the fibre guide channel 12 and are conveyed through the fibre guide channel 12 into the spinning rotor 13. The suction force develops owing to a vacuum, which is generated in the region of the spinning rotor 13 by means of a vacuum source, not shown. The fibres are removed from the spinning rotor 13 through a fibre removal tube 14 as finished yarn 15. Further details of opening cylinders at spinning locations of rotor spinning machines can be inferred, for example, from DE 41 24 714 Al or DE 195 09 743 Al. Fig. 2 shows a card clothing ring 16 which is enclosed laterally by annular collars 17, 18 and has a plurality of teeth 10 on its periphery. The direction of rotation of the card clothing ring 16 is indicated by the direction arrow 27. The teeth 10 are arranged in rows 2 0 which run round the periphery of the card clothing ring 16. The rows 20 of teeth 10 are only shown in portions for reasons of simplification. The teeth 10 of the rows 20 are in each case formed symmetrically to a plane of symmetry along the centre line 21. Further rows are represented by portions of centre lines 21 shown in a dash-dot manner. Centre lines 21 of adjacent rows 20 formed by the teeth 10 have a spacing D from one another, which is 2 mm. The form of the teeth 10 is shown in Fig. 3. The important faces of the teeth 10 are the tooth face 22, tooth back 23 and tooth flanks 24, 25, with only one of the two tooth flanks 24, 25 namely the tooth flank 25 being visible in each case in the view of Fig. 3. The face of the tooth face 22 extends transversely to the centre line 21. The direction of rotation, in which the teeth 10 move, is indicated by the direction arrow 26. By contact with the tooth flank 25, the individual fibres 28 shown by way of example in Fig. 3, of the teeth 10 are entrained and accelerated. In the view of Fig. 2, the tooth flanks 24 and 25 are parallel to one another and parallel to the centre line 21 of the row 20. The tooth flanks 24 and 25 and the centre line 21 of the row 20 form an acute angle K with the direction of rotation of the opening cylinder 4 indicated by the direction arrow 27, said angle being implemented in Fig. 2 at 1.7°. Owing to the oblique position at the angle K to the direction of rotation, the tooth flank 25 in each case advances slightly offset with respect to the tooth flank 24. The alignment of the teeth 10 according to the invention at the angle K improves the detachment of the individual fibres 28 from the fibre tuft 19, the acceleration and the conveyance of the individual fibres 2 8 through the card clothing ring 16 of the opening cylinder 4 up to the opening region 11 of the fibre guide channel 12. The detachment of the individual fibres 28 from the teeth 10 of the card clothing ring 16 is not impeded. Fig 4 shows a portion of a saw tooth wire 30 wound onto the opening cylinder 4. The saw tooth wire 30 is wound in such a way that the centre line 31 extending in its longitudinal direction forms an acute angle s with the direction of rotation of the teeth 32. The direction of rotation is indicated by the direction arrow 33. The configuration and the arrangement of the teeth 32 is such that their advancing tooth flanks 34 form an angle X with the centre line 31 extending in the longitudinal direction of the saw tooth wire 30 and the angle K with the direction of rotation of the teeth 32. In addition to the orientation of the teeth 32 arranged in rows 35 selected by the winding onto the opening cylinder 4, there is an angular position of the tooth flank 34 to the longitudinal direction of the saw tooth wire 30. applies here. In Fig. 4, a drawing to scale has been dispensed with in favour of improved clarification of the angular positions. The subject of the invention is not limited to the embodiment shown in the figures. In particular, the tooth form may be configured in an alternative manner. We Claim: 1. Opening cylinder for rotor spinning machines, comprising a plurality of teeth which are arranged to extend in a row in a continuous spiral-shaped manner on the periphery thereof and are aligned such that their advancing tooth flanks form an acute angle in each case in the direction of rotation with a circle of the opening cylinder described by the rotational path of the tooth, characterised in that the acute angle K is at least 1° and at most 2.5° with respect to the direction of rotation of the opening cylinder (4). 2. Opening cylinder as claimed in claim 1, wherein the angle K is at least 1.5° and at most 2°. 3. Opening cylinder as claimed in either of claims 1 or -2, wherein the teeth (10) are arranged in rows (20), such that a constant spacing D, which is between 1 mm and 2 mm, is formed between the teeth (10) of adjacent rows (20) when the angular position of the tooth flanks (24, 25) remains the same, and the angular position of the teeth (10) coincides with the direction of the rows (20) . 4. Opening cylinder as claimed in claim 1 or 2, wherein the opening cylinder (4) is designed such that the advancing tooth flanks (34) of their teeth (32) in each case form an acute angle X with the direction of the rows (35) of teeth (32). 5. Opening cylinder as claimed in any one of claims 1 to 4, wherein the teeth (32) are part of a one-part card clothing ring (16). 6. The opening cylinder as claimed in any one of claims 1 to 4, wherein the teeth (32) are part of a saw tooth wire (30) which is applied to the basic body of the opening cylinder (4) . 7. Saw tooth wire for opening cylinders as claimed in claim 6, wherein a tooth flank (34) of the teeth (32) of the saw tooth wire (30) in each case forms an acute angle of at least 0.5° and at most 2.5° with the longitudinal direction of the saw tooth wire (30). 8. Saw tooth wire as claimedinclaim 7, wherein the angular position of the tooth flank (34) of the tooth (32) is'produced by shaping the saw tooth wire (3 0). 9. Saw tooth wire as claimed in claim 7, wherein the angular position of the tooth flank (34) of the tooth (32) is produced by material removal. Dated this 20th Day of April, 2005 HIRAL CHAN0RAKANT JOSHI AGENT FOR SAURER GMBH & CO. KG

Documents:

328-mumnp-2005-cancelled pages(30-10-2006).pdf

328-mumnp-2005-claims(granted)-(30-10-2006).doc

328-mumnp-2005-claims(granted)-(30-10-2006).pdf

328-mumnp-2005-correspondence(30-10-2006).pdf

328-MUMNP-2005-CORRESPONDENCE(8-2-2012).pdf

328-mumnp-2005-correspondence(ipo)-(17-08-2007).pdf

328-mumnp-2005-drawing(30-10-2006).pdf

328-mumnp-2005-form 1(30-10-2006).pdf

328-mumnp-2005-form 18(25-04-2005).pdf

328-mumnp-2005-form 2(granted)-(30-10-2006).doc

328-mumnp-2005-form 2(granted)-(30-10-2006).pdf

328-mumnp-2005-form 3(20-04-2005).pdf

328-mumnp-2005-form 3(30-10-2006).pdf

328-mumnp-2005-form 5(20-04-2005).pdf

328-mumnp-2005-form-pct-isa-210(30-10-2006).pdf

328-mumnp-2005-other docment(30-10-2006).pdf

328-mumnp-2005-power of attorney(30-10-2006).pdf

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