Cleaning device for the cleaning of a spin rotor and scraper element

Abstract

The invention concerns a cleaning apparatus for the cleaning of a spin rotor of a spinning station with a cleaning head which can be insertably presented to the spin rotor and on which cleaning head are placed at least two scraper elements. In accord with the invention, the at least two scraper elements are pneumatically extendable, wherein the position of the at least two scraper elements are so secured on the outer circumference of the cleaning head, that the sum of the contact forces which are exerted from the scraper element in a radial direction onto the rotor is zero, or practically zero.

Description

DESCRIPTION

[0001] The invention concerns a cleaning apparatus for the cleaning of a spin rotor in a rotor spinning machine, with a cleaning head which can be insertably presented to a spin rotor on which at least two scraper elements are placed and the invention also concerns a scraper element corresponding thereto.

[0002] U.S. Pat. No. 4,339,914 discloses a cleaning apparatus which is mounted on a service cart which is capable of movement, whereby the said apparatus can be presented to a spin rotor for the cleaning of the same. On the cleaning head of the cleaning apparatus, a scraper is placed, which, by means of a pneumatic cylinder can cleaningly enter into the rotor groove of the said spin rotor. For the cleaning of the rotor groove, the spin rotor is caused to rotate. In order to achieve a sufficient cleaning effect, the scraper must be subjected to pressure to achieve a correspondingly sufficient force of cleaning contact. On this account, the spin rotor receives an asymmetric loading, which especially contributes to a tilting of the rotor in its bearing, and because of the necessity of rotating the rotor, a one-sided, operationally untypical loading of the spin rotor results. As rotor bearing technology advances, and with the development of aero and magnetic bearings, the bearings have become more sensitive in regard to such non-typical loadings.

[0003] The DE 26 29 161 shows various embodiments of cleaning apparatuses, these being equipped with different accoutrements including scrapers, brushes and compressed air nozzles. In one embodiment, two oppositely situated scraper elements can penetrate into the rotor groove. In this arrangement, the scraper elements are fastened on one end on leaf springs, while the other end thereof is affixed to a pivoting axle. In order to insert the cleaning head, the leaf springs are pretensioned in the direction of the pivot axle, so that the scrapers can penetrate through an opening in the rotor bowl. After the penetration, the axle is rotated and by centrifugal force, the scrapers withdraw from the leaf springs until the said scrapers enter the rotor groove. Because of the spring loading, the contacting force of the scrapers is essentially determined by the said centrifugal force. Due to the resilient support, the scraper elements can begin to oscillate inside the rotor groove, so that the cleaning effectiveness cannot be uniform. The adjustment of the contacting force by means of changing the centrifugal force is limited in its possibilities and hence a secure application of the cleaning elements in the rotor groove cannot be assured.

[0004] On this account, it is purpose of the invention to provide a cleaning apparatus for the cleaning of a spin rotor, wherein the cleaning head is constructed in a very compact manner, and wherein a sufficient contacting force of at least one scraper element within the rotor groove is assured. Further it is within this purpose, that during the cleaning of the spin rotor the least possible force is to be exercised against the rotor bearing. A primary objective of a scraper element corresponding to the invention is to properly direct the application of force for the cleaning of the rotor.

[0005] This purpose, is achieved by the features of the independent claims.

[0006] In accord with claim 1, a cleaning apparatus with two scraper elements is proposed for the cleaning of a spin rotor. With these two scraper elements, the inner wall, especially the rotor groove of the spin rotor bowl is to be scraped. For cleaning, either the cleaning head is to be rotated by an appropriate drive, or the spin rotor itself must turn while the cleaning head with its scraper elements is held motionless. Advantageously, however, it is the cleaning head which should be rotated, since in this way, with an opened spinning box, the already applied brake for holding the rotor motionless need not be again released, in order to rotate the spin rotor. The sum of the force vectors, which forces arise on the rotor in a radial direction from the contact force of the scraper element, is zero, or nearly zero. Thus no tilt moment is generated on the spin rotor and the rotor bearing is not loaded, or only slightly loaded, during the cleaning operation. The protection of the rotor bearing is especially critical if the bearing design is based on aero or magnetic principles. Very little tolerance for bearing displacement is allowed and as a rule, stationary loadings are more likely to bring forth damage than the dynamic loadings for which the bearing was designed.

[0007] In graphic terms, the pneumatically extendable scraper elements protrude in the manner of claws following the insertion of the cleaning head into a rotor bowl. Thus, the outside dimensions of the rotor head are to be kept appropriately small to allow its entry into the rotor bowl and to allow the cleaning head to penetrate even small openings in the rotor bowl. Once in place, the extended scraper elements spread themselves within the rotor bowl, which bowl structure captures the generated forces almost completely, without allowing the rotor shaft to be subjected to a tilting or coupling moment. In one embodiment, provision has been made, that the rotor head, in a direction radial to the spin rotor, is supported on floating bearings, so that upon the contact of the scraper against the rotor head, a self-centering effect takes place. Advantageously, the rotor head is mounted on a run-out unit, which in turn is placed on a service cart which has access to each spinning station.

[0008] The scraper elements can be located on the circumference of the cleaning head in various angular positions allowing the resultant forces to be completely or nearly completely removed. A separation of about 180° can be mentioned as advantageous, wherein the scraper elements lie across from one another on the rotor wall. Or three scraper elements can separated at not more than 120° from one another, so that their combined application of force on the rotor bowl is likewise self compensating.

[0009] In accord with a first aspect of the invention, the force components of the contacting action of several cleaning elements against a spin rotor head result in mutual compensation. In accord with a second aspect, the pneumatics are integrated in a compact manner within the extendable cleaning head for the placement of at least one scraper element. Both aspects can be realized separately or advantageously in combination. The compact mode of the pneumatic supply equipment which is integrated in the cleaning head is presented in the following as an embodiment, but however, can be also employed in the case of a cleaning head having at least one scraper.

[0010] Advantageously, the at least two scraper elements are extended by a single, compressed air driven piston. For this action, principally one pneumatically operated element is required, wherein all installed scraper elements can be activated and to bring about a very compact construction of the cleaning head.

[0011] Very advantageously, the piston, in a case of at least one scraper element, is displaced in a radial direction in reference to the spin rotor, while the at least one scraper element principally executes a radial extension motion. By means of the special reversal of this motion the constructed depth of the cleaning head is shortened, and this leads to an even greater degree of compactness. Particularly advantageous is that at least one scraper element can pivot in its setting on the cleaning head. Because of the pivoted support of the scraper element, a large pivoted sweep of the element becomes possible thereby allowing applications to diverse types of rotors with considerably different rotor diameters. In addition, the penetration into the rotor groove is facilitated, if the rotor bowl bottom is designed to be particularly flat, or if the fiber slip walls have especially great circumferential lengths or are installed at an angle.

[0012] In a particularly advantageous manner, the retraction of the at least two extended scraper elements is carried out after the reduction of the air pressure for the pneumatic placement by means of the contractive force of a single O-ring, so that a separate retraction need not be carried out for each scraper element. If the securement and the retraction of at least one exchangeable, seated scraper element is carried out by one O-ring, then an exchange of obsolete scraper elements can be accomplished by a simple removal of the O-ring, the insertion of a new scraper element and the replacement of the said O-ring. In this way it is not necessary, to have recourse to tools or parts of the cleaning head—with the exception of the O-ring—for disassembly and reassembly. Thus the result is, first, a very rapid maintenance operation and second, upon changing the spin rotor type, then special, scraper elements can be installed to fit a new spin rotor type.

[0013] Advantageously, by means of compressed air nozzles, the contamination particles loosened by the scraper elements are blown out of the rotor bowl.

[0014] A scraper element, in accord with the invention, particularly designed for the cleaning of a spin rotor on an open end spinning machine, possesses a pivoting axle and a scraping surface. The scraper element consists of two legs, bound together, wherein at one end of a first leg, the pivot axle is found, while on one end of the second leg the scraping surface is formed. Provided on one end, remote from these said ends, on at least one of these legs, is a control surface for rotating the scraper element about the pivot axle. In this way, a scraper element has been created which, in its installed condition and considering the generated and exercised forces present, is very simple to control. By means of the control, the scraper element is swung about the pivot axle and pivoted into the rotor. The scraper surface displaces itself, when this occurs, in a direction toward the rotor groove, and is then so positioned, that upon a relative motion between the said scraper element and the rotor, the rotor groove is cleaned. The torque which can be applied and forces are very advantageously diverted onto the scraper element by the arrangement of the rotational axle, the control surface and the scraper surface. In this way, a proportional, but still powerful pressure can be exercised by the scraper surface on the rotor groove, whereby the cleaning action can be controlled in a highly specific manner.

[0015] It is of particular advantage, if the legs close an angle of less than 120°. In this way, even by small spin rotors a particularly simple pivoting of the scraper surface into an effective position is possible.

[0016] If the two legs are bound on their ends with one another, and at the same time the control surface finds itself essentially at the end of that same leg, which has the scraper surface, then a particularly direct input of power is available for the scraper surface and correspondingly, this force is exercised on the location to be cleaned of the spin rotor.

[0017] If the scraper surface is arranged on the leg angularly, then, a particularly simple and effective cleaning is possible in the case of especially deep rotors, or where rotors with large backcuts or complicated rotor groovings are employed.

[0018] It is particularly of advantage, if the scraper is designed to be clawlike, with an essentially concave inner side and an essentially convex outer side.

[0019] With this arrangement, the rotor rim is particularly aggressively attacked by the pivoting in of the scraper element and the rotor groove is very simply acted upon by the tilt-motion of the scraper element moving about its pivot axle.

[0020] In the defining installation of the scraper element, the pivot axle of the scraper element is remote from the axle of the rotor, so that a central control of several scraper elements is possible with one piston. The control is carried out, in this case, in proximity to the rotor axle, on which several scraper elements are closely aligned. The pivoting axle of the scraper element is located in a place in which sufficient space is allowed for the fastening of the scraper element.

[0021] If the pivot axle is placed in a groove-shaped recess of the scraper element, then a very easy replacement of the said scraper element is made possible. This would be required in case of abrasive wear, or if a different kind of scraper element need be installed. In the case of this groove-shaped recess, the scraper element can be clipped onto a fixed axle of the cleaning apparatus and in this manner be fastened for the application of cleaning. Upon the exchange of the scraper element it can then be released from the clip and removed from the cleaning apparatus. The groove-shaped recess is, in this respect, especially of advantage for a quick maintenance visit at the cleaning apparatus.

[0022] If the scraper has a detent surface between the pivot axle and the control surface, then a defined positioning of the scraper during its idle period is possible. This is advantageous in order to avoid a collision of the cleaning apparatus with the spin rotor upon inserting the cleaning apparatus therein.

[0023] Because of capability of a now simplified manufacture, it is of advantage, if the control surface of the scraper element and/or the detent surface, are essentially designed as flat surfaces.

[0024] A further control surface of the scraper element is placed, advantageously, on the concave inner side of the scraper, in order to be able to retrieve the scraper element from the workstation during an idle period. Although the first control surface of the scraper element is intended for the purpose, of bringing the scraper element out of the idle position into the operational position, the second control surface has the converse purpose of bringing the scraper element out of the operational position back into the idle position.

[0025] It is particularly advantageous in this matter, if the control surface for the retrieval of the scraper element is designed with a domelike curvature. In this way, it can act with an O-ring, which exercises a springlike force on the scraper element in the direction of the idle position.

[0026] In order to bring a directed and defined force onto the scraper surface and at the same time design the said scraper element to be economical in its manufacture, it is preferable if the scraper element is furnished with reinforcing ribs.

[0027] Plastic material, in particular polyamides, have shown themselves well as a material for the scraper element. In order to procure a scraper element of the greatest possible operational life, it is to advantage if the scraper element is reinforced with fibers.

[0028] If the scraper element is so constructed, that it can be exchangeably fastened into the cleaning apparatus as far as possible without tools, then a very economical maintenance of the cleaning apparatus has been achieved.

[0029] Insofar as the scraper element is so formulated, that it can be provided for a group of different rotor diameters or for different kinds of rotors, then the exchange of the scraper element, even in the case of an exchange of the spinning means is generally not required. Even in this case, the mounting and the maintenance costs are reduced.

[0030] The invention will be more closely described and explained with the aid of embodiments shown in the illustrating figures. There is shown in:

[0031] FIG. 1 an axial section is shown in an enlarge presentation through a spin rotor in stillstand as well as an insertable, cleaning head which is mounted on a startup cart,

[0032] FIG. 2 a plan view in the direction of the arrow 2 of FIG. 1, as seen externally onto the cleaning head,

[0033] FIGS. 3A to 3F a second embodiment of a cleaning head,

[0034] FIGS. 4A and 4B a third embodiment of a cleaning head,

[0035] FIG. 5 a perspective view of a scraper element, and

[0036] FIG. 6 a side view of a scraper element.

[0037] The apparatus 1 depicted in FIGS. 1 and 2, serves for the cleaning of a motionless spin rotor 2, which, preferentially is held still by the action of a (not shown) braking means. Normally what is involved here is a spin rotor 2 having a small diameter, preferably less than 30 mm, as is conventionally used today.

[0038] The apparatus 1 contains a cleaning head 3, which, advantageously is a component of a (not shown) traveling service cart. This cleaning head 3 is, in case of maintenance attention, displaceable in the directions B and C and, upon requirement, can be inserted through the open forward side 4 into the interior 5 of the spin rotor 2, as is indicated by the dotted outline of the cleaning head shown in position 3′. The cleaning head 3 serves for cleaning the fiber collection groove 6 in the interior 5 of the spin rotor 2 at specified intervals during an interruption of the spinning procedure. During spinning operation, the fiber collection groove 6, is the collection zone for fibers. The cleaning head 3 possesses several mechanical cleaning elements 7, advantageously designed as scrapers, as well as a plurality of compressed air nozzles 8. The mechanical cleaning elements 7, in accord with the position 7′ designated in dotted lines, can be placed within the fiber collection groove 6, while the compressed air nozzles 8 are located either stationary on the cleaning head 3 or made to approach the said fiber collection groove 6 to a certain degree.

[0039] In the axle of the cleaning head 3 an axial boring performs as a compressed air connection 9, through which the necessary compressed air for the cleaning of the spin rotor 2 can be introduced in a yet to be described manner. Since the spin rotor 2, as has already been mentioned, stands still during the cleaning procedure, the cleaning head 3 can be connected to a (not shown) rotational drive mechanism A. In this way, the entire circumferential area of the fiber collection groove 6 can be reached by the cleaning elements 7 and air nozzles 8.

[0040] The spin rotor 2 is encased in rotor housing 10, which encompasses a suction chamber 11, which, upon the operation of the open end spinning aggregate, is tightly closed. The exhaust direction of the suction is designated by D, which, upon the operation of the open end spinning aggregate serves, in first line of importance, the purpose of feeding by air transport the fiber material to be spun into the fiber collection groove 6. A shaft 12 is available to the spin rotor 2, which, in a sealed manner, penetrates the back wall of the rotor housing 10 and in a manner not shown, is supported and driven on bearings outside of the rotor housing 10.

[0041] Since the individual components of the spinning aggregate are continually involved with low tolerance clearances, provision has been made, that the cleaning head 3, upon introduction into the interior 5 of the spin rotor 2 is precisely aligned relative to the fiber collecting groove 6. To this end, in the interior 5 of the spin rotor 2, an axial detent 13 is located against which the cleaning head 3 abuts. The said axial detent 13 also serves for the radial centering of the cleaning head 3. The axial detent 13 is contoured to be slightly conical in form whereby a complementary conical contact surface 14 of the cleaning head 3, in a self centering manner, lies against the said axial detent 13. The cleaning head 3, in this way, is advantageously installed in a springlike way (which is not shown) and is in precise alignment to the axle of the spin rotor 2 as well as to the plane defined by the circumference of the fiber collection groove 6.

[0042] Centered within the axle of the cleaning head 3 is placed a movable valve stem 15, which, when the contact surface 14 of the cleaning head 3 lies against the axial detent surface 13 of the spin rotor 2, is pressed somewhat further in the direction of the arrow E into the cleaning head 3, as may be seen in the dotted line position 15′ of FIG. 1. This movement provides a free opening around a valve head 16 for the compressed air inlet line 9. This opening is evident in the valve head position 16′ in the interior 5 of the spin rotor 2. When the axial detent surface 13 becomes functional, at the same time the mechanical cleaning element 7 and the compressed air nozzles 8 become connected with the compressed air inlet opening of fitting 9. Thereby the compressed air nozzles 8 make available the compressed air necessary for the cleaning, while the mechanical cleaning elements 7 are forced into the fiber collection groove by means of this said compressed air. The invention, however, does not exclude the possibility, that the compressed air nozzles can also approach the fiber collection groove by a certain separating distance.

[0043] For this purpose, as is especially clearly shown in FIG. 1, the mechanical cleaning elements 7 as well as the compressed air nozzles 8 are served by one, displaceable piston in a pneumatic cylinder.

[0044] There is to be found on the cleaning apparatus 1, shown only by an indicating outline, a covering 17, which, in the activated state of the cleaning head 3, lies against the front side of the rotor housing 10, so that the effective suction in the interior 5 of the spin rotor can remove the particles of the contamination which have been loosened by the cleaning process.

[0045] Finally, mention should be made, that before the insertion of the cleaning head 3, it is to advantage, to blow out possible rings of fibers which could be found in the interior of the spin rotor 2 upon cessation of its rotation. On this account, it is a practical matter, to provide (in a manner not shown) for the apparatus 1 an additional separate compressed air nozzle, which blows into the interior 5 upon the opening of the spinning aggregate, as the spin rotor 2 is subjected to braking so that any possible fiber ring would be dispersed. Such a nozzle, for instance, could be mounted on the arm which carries the cleaning head 3 and would be activated as soon as the cleaning head 3 approaches, but is still outside of the spin rotor 2.

[0046] Thus, an apparatus for the cleaning of a stationary, open end, spin rotor is provided, with at least one cleaning head connected to a rotational drive, which cleaning head can be centrally inserted into the interior of the said spin rotor and which cleaning head has at least one mechanical cleaning element which can be placed against a fiber collection groove of the spin rotor as well as at least one compressed air nozzle which can be directed against the said fiber collection groove, both of which can be connected to one compressed air entry in a boring in the axle of the cleaning head, whereby, for the cleaning head 3, an axial detent surface 13 is provided in the spin rotor 2, by means of which, in its functional state, both the at least one compressed are nozzle 8 as well a the at least one mechanical cleaning element 7 are connected with compressed air entry 9 and at least the mechanical cleaning element 7, by means of compressed air is presented to the fiber collection groove 6. In the embodiment the axial detent surface 13 is to be found in the interior 5 of the spin rotor 2. Also the at least one compressed air nozzle 8 can be brought to confront the fiber collection groove 6. Advantageously, the axial detent 13 serves to radially center the cleaning head 3.

[0047] The FIGS. 3A to 3F show, in succession:

3A a perspective view of a retracted scraper 21 of a cleaning head 20,
3B a front view of a retracted scraper 21 of a cleaning head 20,
3C a cross-section A-A of a retracted scraper 21 of a cleaning head 20,
3D a cross-section A-A of an extended scraper 21 of a cleaning head 20,
3E a profile view of a second embodiment of a cleaning head 20, and
3F a cross-section through line BB of cleaning head 20 in FIG. 3E.

[0048] The cleaning head 20 is exchangeably placed on an extendable apparatus and by means of a coupling piece 22 is connected to a drive motor. Such an extendable apparatus with a drive motor has been disclosed by DE 102 05 666.8, and acknowledgement is herewith given regarding the content thereof, where concern relative to an extension and placement unit is made. In the cleaning head 20 are pivotably supported two pneumatically extendable scrapers 21. FIG. 3A shows the scraper 21 in a partially extended condition. As is evident from the cross section of FIG. 3D, the coupling piece 22 has a central compressed air connection 23 and threaded, centering borings 34. After the setting of the coupling piece 22 in a recess with a compressed air connection (of an external extension means not further described) the coupling piece is secured and properly aligned by means of set screws, which are threadedly engaged in the said centering borings 34.

[0049] During pivoting motion and cleaning operation, the scrapers 21 are supported and guided by the side members 24. In one of the side members 24 is provided a compressed air channel 27 (FIG. 3F), which delivers compressed air to one forward compressed air nozzle 25 on the forward side of the side member and to two rear compressed air nozzles 26 on the side of the side member 24 (see FIG. 3A). In the case of one embodiment, it is possible that in both side members 24, a corresponding channel 27 and nozzles 25, 26 can be provided in a symmetrical arrangement.

[0050] The extension apparatus, which is not described here in further detail, has a position sensor, that is, a propinquity switch, which announces to a control center, that the extension apparatus has extended to its predetermined limit and reached the desired position. By means of this positional announcement, the determination is made, that the cleaning head has completed its insertion into the rotor bowl, so that, by means of a solenoid valve, the compressed air may be applied for the extension of the scraper 21. In another embodiment, provision can be made, that, instead of the position sensor or in addition to the position sensor, an activation means 15, 16, as shown in FIG. 1 can be provided. In an embodiment such as shown in FIG. 1, an axial alignment of the cleaning head is assured, while in the case of an embodiment with the sensor, a detent of the cleaning head on the rotor bowl base is not necessary and thus axial forces, for example, acting on an air bearing are avoided. In an embodiment, not pictorially presented here, the extension unit can possess a floating bearing arrangement for the cleaning head, which acts radial to the spin rotor, so that after the extension of the scraper, that is, during the cleaning operation, a radial self-centering takes place between the rotor and the cleaning head.

[0051] Following the insertion of the cleaning head 20 into a rotor head (not shown here), the forward compressed air nozzle 25 blows compressed air into the rotor groove of the rotor bowl, while the rear compressed air nozzles 26 direct an air stream on the fiber sliding wall of the rotor teller. The side support members 24 rest upon a base plate 28, onto which, in turn, the coupling piece 22 connects. In the base plate 28, is cut a longitudinal groove 35, in which rest the lower sides of the scraper, when in the retracted position. In the end zone of the groove 35, are installed two pivot axles 30 on which the scraper 21 is pivotably supported. As presented, the axles 30 are the cylindrical mid-portions of cylinder head screws screwed into the base plate 28. Instead of these, however, drift pins or splined pins could be inserted into the borings in the base plate 28. A U-shaped groove 31 of the scraper only partially encompasses the axle 30, so that the scraper 21, after being swung out about 90° from the axle 30 can be taken out and exchanged. In this way, a very simple and rapid exchange of worn scrapers 21 for other scrapers can be carried out.

[0052] The side members 24 are encompassed at their bases by an O-ring 29, which fits into an O-ring groove 36 around the two said side members (see FIG. 3E).

[0053] In the position depicted in FIG. 3C of the scrapers 21, these have been pressed back into the basic position shown by means of the continuous sections of the O-ring running between the two side parts 24. In a non-loaded situation, the O-ring 29 prevents also a 90° swinging out of the scraper, so that, by the action of the O-ring 29 and at the same time being restrained by the axles 30, the scraper 21 is securely seated in the cleaning head 20 and its falling out therefrom is prevented.

[0054] Through the coupling piece 22 and the base plate 35, penetrates a cylindrical boring, which extends itself partially from behind into the side pieces 24 (FIG. 3D). In the cylinder boring 33 a piston 32 slides, which piston, upon the application of compressed air at the compressed air connection 23, is displaced forward. By means of the said forward displacement of the piston 32, the pivotable scraper 21 swings about its axle 30. FIG. 3C shows the basic position of the piston 32 and the scraper 21 at zero pressure. Fig. D shows the position of the piston 32 and the scraper 21 after the application of compressed air from the compressed air fitting 23. In this state, the piston 32 is partially displaced forward and the scrapers 21 are correspondingly partially pivoted forward about the axles 30. In the cylinder boring 33 is placed (not shown) a detent, which blocks the travel of the piston 32, so that first, the piston is not pushed out of the boring 33 and second, the side wall of the piston 32 does not continue movement between the two scrapers 21. In this way, assurance is given, that by the lever action of the a scrapers 21, which are prestressed by means of the O-ring 29, the undersides of the scraper 21 press the piston back into the originating position as soon as the air pressure is reduced. The clawlike extension of the scraper 21, caused by the projection of the piston 32, is carried out over a wide pivoting zone, so that a cleaning head 20 with the same scraper 21 can be installed for different rotor diameters.

[0055] Further, by means of varying the pressure of the air, which acts upon the piston, the corresponding lever action and hence the contact pressure of the scraper points on the rotor groove can be adjusted over a wide range.

[0056] FIGS. 4A and 4B show a cross-sectional view and a front view of a third embodiment of a cleaning head 40. Two scrapers 41 can, in this embodiment, be laterally separated within linear guides by a piston 48. In FIG. 4A a spin rotor 42 is additionally schematically indicated into which the cleaning head 40 has already been introduced before the scrapers 41 have been extended. The cleaning head 40, corresponding to the cleaning head 20, has a coupling piece 43 with a centrally bored compressed air connection. Penetrating the coupling piece 43, through a base plate 44, and partially between the side pieces 45, runs a cylindrical guide for a piston 48. The thrust of the piston 48 is limited by projections on the side pieces 45, so that the piston 48, upon application of pressure, is not propelled out of the said guide cylinder. In the side pieces is formed, respectively, a groove 46 into which guide projections 47 protruding from both sides of the scrapers 41 engage. The side pieces 45 serve for the guidance and securement of the scrapers 41. An O-ring 49 is stretched circumferentially about scrapers 41, so that, in a pressure-free condition, the said O-ring 49 forces the scrapers 41 back into their basic position shown in FIG. 4A. In this way, unextended scrapers 41 can be inserted through the free opening of the rotor bowl. When the scrapers 41 extend and retract, the smoothed inclined sliding surfaces of the apex of the piston 48 and the complementary back sides of the scrapers 41 slide on one another, thus converting the forward or backward motion of the piston 48 into side directed movements of the scrapers 41. For an exchange of the scrapers 41, the O-ring is removed and the scrapers can be pulled out sideways from the groove 46. In this way, a quick exchange or replacement of the scrapers 41 becomes possible.

[0057] The designs of the axial detent surfaces, as presented in FIGS. 1 and 2, with the radial alignment by means of the said detent surfaces and/or the compressed air admission from movement of the valve head 16 can be applied to the designs of the cleaning heads in accord with the FIGS. 3 and 4.

[0058] FIG. 5 shows a perspective presentation of an invented scraper element 21. The scraper element 21 has a first leg 37 and a second leg 38. The two legs 37, 38, are bound together on one end with each other, so that a hooklike or claw-shaped component is formed. On the free end of the leg 37 is to be found the groove 31, with which the scraper element 21 can be secured in the cleaning head 20 of FIG. 3. The free end of the second leg 28 has a scraping surface 39, which, during the cleaning of the spin rotor, is extended, pivoted and inserted into the spin rotor. Thereafter, due to relative motion between the spin rotor and the scraper element 21, a scraping motion is effected in the spin rotor. The scraper element 21 consists of an inner wall, which is peripherally bordered by a rib 51. With this construction, an especially high degree of stability is achieved for the scraper element 21.

[0059] On the ends of the legs 37 and 38 is located a control surface 52. By means of the control surface 52, the scraper element 21 can be pivoted about the axle 30 of FIG. 3. The axle 30 corresponds with the pivot axle 55 of the scraper element 21.

[0060] Between the control surface 52 and the groove 31 is to be found a detent surface 53, placed on the first end 37. The detent surface 53 defines the resting position of the scraper element 21. The scraper element 21 strikes, in this arrangement, with its detent surface 53, against an abutment component of the cleaning head 20, whereby the scraper element 20 is secured in its idle position, in order to allow the cleaning head 20 to be inserted into the spin rotor bowl.

[0061] FIG. 6 shows a profile view of the scraper element 21 as derived from FIGS. 5, 3. The scraper element 21 consists of the two legs 37 and 38, which are connected at one end with each other. An the leg 38, the scraper surface 39 is angularly formed. By an arrangement of this kind of the scraper element 39, its engagement in the rotor groove is facilitated. The detent surface 53 is inserted between the groove 31 and the control surface 52 of the leg 37. The control surface 52 is placed on that end of the leg 37 remote from the groove 31. In the groove 31 runs the pivot axle 55 of the scraper element 21. Because of the said groove 31, the changing of the scraper element 21 is very easily possible.

[0062] The scraper element 21 can simply be clipped into the axle 30 (FIG. 3) and the scraper element 21 is subsequently rotatable about the axle 30, which corresponds to the pivot axle 55. In order to avoid a collision with an immovable component of the cleaning head 20, the end of the leg 37 is rounded-off concentrically to the said pivot axle 55.

[0063] In order to be able to retract the scraper element from its operational position into its idle position, an additional control surface 50 of the scraper element 21 is located on the concave, inner side of the scraper element 21. While the first control surface 52 of the scraper element 21 is adapted to bringing the scraper element 21 out of its idle position into the operating position, the second control surface 50 is provided for the purpose of bringing the scraper element 21 out of its idle station and into the operating position. The functioning of this explained in greater detail in FIG. 3.

[0064] Because of the dome shaping of the control surface 50, this can, for example, work together with an elastic O-ring, which exercises a springlike force on the scraper element, in the direction of returning the scraper element 21 to its idle position.

[0065] The present invention is not limited to the presented embodiments. Alterations within the bounds of the patent claims are allowable at any time.

Claims

1. A cleaning apparatus for the cleaning of a spin rotor (2, 42) of a spinning station, having a cleaning head (3, 20, 40), which is presentable to the said spin rotor (2, 24) and on which cleaning head (3, 20, 40) at least two scraper elements (7, 21, 41) are placed, therein characterized in that the at least two scraper elements (7, 21, 41) are extendable, whereby the position of the at least two scraper elements (7, 21, 41) on the outside circumference of the cleaning head (3, 20, 40) is so secured that the sum of the contacting forces exercised in a radial direction from the scraper elements (7, 21, 41) on the rotor (2, 42) is zero or nearly zero.

2. A cleaning apparatus in accord with claim 1, therein characterized, in that the scraper elements (7, 21, 41) are pneumatically extendable.

3. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that at least one pair of pneumatically extendible scraper elements (7, 21, 41) is provided, whereby the two scraper elements scraper elements of each pair are offset about 180° from one another.

4. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that three extendable scraper elements are provided, which are circumferentially separated one from the other by about 120°.

5. A cleaning apparatus in accord with one of the foregoing claims, characterized by a drive unit for the rotation of the cleaning head (3, 20, 40).

6. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that the scraper elements (21, 41) are extendible by means of a mutual, compressed air loaded piston, (32, 48).

7. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that the piston, (32, 48) is displaceable in the axial direction of the spin rotor.

8. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that the piston (48) exhibits one or more inclined slip-walls upon which the scraper element (41) slides for extension.

9. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that the at least two scraper elements (21) are pivotably supported and swingable by means of the piston (32).

10. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that the scraper elements (21, 41) are constructed in a bow or claw shape.

11. A cleaning element in accord with one of the foregoing claims, characterized by at least one spring element (29, 49), which retracts one or more scraper elements (7, 21, 41) upon the reduction of the air pressure.

12. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that the springlike element (29, 49) is an O-ring.

13. A cleaning apparatus in accord with one of the foregoing claim, therein characterized, in that the scraper elements can be exchangeably seated without the use of tools.

14. A cleaning apparatus in accord with one of the foregoing claims, therein characterized in that the at least one springlike element (29, 49) secures the replaceable scraper element (21, 41) on the cleaning head (20, 40).

15. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that on the cleaning head (3, 20) at least one compressed air nozzle (8, 25) is supplied for the blowing out of the rotor groove (6) of the rotor (2, 42).

16. A cleaning apparatus in accord with one of the foregoing claims, therein characterized, in that on the cleaning head (20) at least one compressed air nozzle (26) is provided for blasting the slide wall of the rotor.

17. A scraper element for the cleaning of a spin rotor of an open end spinning machine, with a pivot axle (55) and a scraper surface (39), therein characterized, in that the scraper element (21) possesses two legs (37, 38) which are bound together, wherein, on one end of the first leg (37) is placed a pivot axle (55), on one end of the second leg (38) is created the scraper surface (39) and on an end, distal from these said ends of the legs (37, 38), a control surface (52) is placed for the movement of the scraper element (21) about the said pivot axle (55).

18. A scraper element in accord with the previous claim, therein characterized, in that the legs (37, 38) close an angle of less than 120°.

19. A scraper element in accord with one of the foregoing claims, therein characterized, in that both legs (37, 38) are bound with one another at their ends.

20. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper surface (39) on the leg (37, 38) is installed at an angle.

21. A scraper element in accord with one of the foregoing claims, therein characterized in that, the scraper element (21) is designed to be clawlike with an essentially concave inner side and an essentially convex outer side.

22. A scraper element in accord with one of the foregoing claims, therein characterized, in that in an installation of the pivot axle (55) in accord with the invention, the said axle (55) is remote from the rotational axis of the rotor.

23. A scraper element in accord with one of the foregoing claims, therein characterized, in that in an installation in accord with the invention, the control surface (52) of the scraper element (21) is proximal to the rotor axis.

24. A scraper element in accord with one of the foregoing claims, therein characterized, in that the pivot axle (55) is placed in a groove shaped recess (31) of the scraper element (21).

25. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper element (21) possesses a detent surface (53) between the pivot axle (55) and the control surface (52) for the purpose of defining the positioning of the scraper element (21) in its idle period.

26. A scraper element in accord with one of the foregoing claims, therein characterized, in that the control surface (52) of the scraper element (21) and/or the detent surface (53) is essentially flat.

27. A scraper element in accord with one of the foregoing claims, therein characterized, in that a control surface (50) for the retraction of the scraper element (21) is placed on the concave inner side of the scraper element (21).

28. A scraper element in accord with one of the foregoing claims, therein characterized, in that the control surface (50) is designed to be dome shaped for the retraction of the scraper element (21).

29. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper element (21) possesses reinforcement ribs (51).

30. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper element (21) is made of plastic, in particular, of a polyamide.

31. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper element is reinforced with fibers.

32. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper element (21) is designed to be exchangeable.

33. A scraper element in accord with one of the foregoing claims, therein characterized, in that the scraper element (21) is provided for a group of different rotor diameters.