Title of Invention

"DEVICE FOR CONTROLLING A LINE OF DRAWING ROLLERS OF A TEXTILE MACHINE AND METHOD THEREOF"

Abstract

Device for controlling a line of drawing rollers of a textile machine comprising two drawing rollers (1 and 2) mounted on bearings (6) and a pressure roller (3), which is pressed against the two drawing rollers (1 and 2), and optionally a calender roller (16) cooperating with a pressure roller (18), characterized in that one of the drawing rollers (1) is driven in rotation by a notched belt (8) meshing with a pinion (7) that is integral with the first drawing roller (1), and the other roller (2) is driven in rotation by a friction device.

Full Text

The present invention relates to device for controlling a line of drawing rollers of a textile machine and method thereof The present invention relates to the field of textile machines, in particular drawing machines and finishers, and concerns a method for controlling a draw frame of a textile machine. The invention also relates to a device for implementing this method. Lines of drawing rollers in machines, such as chain gills, screw intersections, and circular or spike gills, and finishers, such as rubbing frames and fly frames, at present generally comprise an assembly of two fluted metallic rollers, called drawing rollers, against which a roller covered with a resilient covering, called a pressure roller, is pressed. The drawing roller, which is located in the immediate vicinity of the fibre control zone, has a smaller diameter than the adjacent drawing roller, in order to keep the distance separating the draw frame from the fibre control zone as short as possible. Each roller has, at its end, a pinion, via which it receives its rotational movement. A draw frame of this type, the configuration of which has been known from some time, is outlined, for example, in FR-A-1 456 485, in which the pinions of each drawing roller are connected to one another by an intermediate pinion. There are also embodiments according 'to which one of the pinions is a bell pinion, within which the other pinion meshes. Moreover, more recent configurations have provided for a lubricated housing containing an intermediate shaft to be fitted to two pinions, in order to connect the pinions of the two drawing rollers. This solution lias the advantage of allowing the drawing rollers to operate at higher rotational speeds, and therefore of increasing the output of the textile machines. On the other hand, it has the drawback of being expensive, of requiring a perfect seal, and of causing the moving members to overheat. Furthermore, known devices for driving drawing rollers in rotation seek to impose the same peripheral speed on each of the drawing rollers, such that the pressure roller that is brought into contact with the two drawing rollers also acquires this same peripheral speed. They are, however, never entirely successful in this respect, given the uncontrollable deformation of the resilient material covering the pressure roller. Very slight differences in the diameter of a drawing roller, for example, which are inevitable, taking into account machining precision and acceptable mechanical tolerances, thus create very slight differences in the peripheral speed of one drawing roller relative to another. The resilient material of the pressure roller is required to compensate for these slight differences in speed by its deformation, which causes overheating of the moving members, a pulsation that may result in irregularities in the ribbon or the rove produced by the textile machine, premature wear of the coverings of the pressure rollers, overloading of the control pinions of the lubricated housing, resulting in premature wear thereof, overheating and an increase in operating noise, as well as overheating of the lubricant liquid and rapid wear of the seals, leading to leakages of oil or fluid grease. Moreover, the process of replacing a worn or deformed drawing roller currently entails dismantling the lubricated housing, which is time-consuming and costly. The object of the present invention is to overcome these drawbacks by proposing a novel method for controlling a draw frame of a textile machine, and a device for implementing this method, allowing manufacturing costs to be reduced, and drawing rollers to be dismantled and reassembled quickly. For this purpose, the method for controlling a draw frame of a textile machine, comprising two drawing rollers and a pressure roller, which is pressed against the two drawing rollers, and optionally a calender roller cooperating with a pressure roller, is characterised in that it substantially consists in driving one of the drawing rollers in non-slip rotation, and in driving the other drawing roller in friction rotation. The invention also relates to a device for implementing this method, in the form of a draw frame comprising two drawing rollers and a pressure roller, which is pressed against the TWO drawing rollers, and optionally a calender roller cooperating with a pressure roller, chai-acterised in that one of the drawing rollers is driven in rotation by a notched belt meshing with a pinion that is integral with this first drawing roller, and the other drawing roller is driven in rotation by a friction device. A better understanding of the invention will be facilitated by the following description, which relates to preferred embodiments, given by way of non-limiting examples, and explained with reference to the accompanying schematic drawings, in which: Figures 1 to 3 are plan views illustrating the kinematic chains of three variations of a draw frame according to the invention; Figure 4 is a lateral elevation of a draw frame according to the invention; and Figure 5 is an illustration of the assembly of a drawing roller according to the invention. According to the invention, and as shown in Figures 1 to 5 of the accompanying drawings, the method for controlling a draw frame of a textile machine, comprising two drawing rollers 1 and 2 mounted on bearings 6 and a pressure roller 3, which is pressed against the two drawing rollers 1 and 2, and optionally a calender roller 16 cooperating with a pressure roller 18, substantially consists in driving one of the drawing rollers 1 in non-slip rotation, and in driving the other drawing roller 2 in friction rotation. This method is implemented by a device in the form of a draw frame comprising two drawing rollers 1 and 2 mounted on bearings 6 and a pressure roller 3, lined with a resilient coating, which is pressed against the two drawing rollers 1 and 2, and optionally a calender roller 16 cooperating with a pressure roller 18. The first drawing roller 1 has a slightly smaller diameter than the second drawing roller 2, so that the distance separating the fibre control zone 4 and the fibre pinching line, which line is formed by the contact zone of the pressure roller 3 against the drawing roller 1, is as short as possible. The drawing rollers 1 and 2 are helically fluted and are mounted on rolling bearings ('Figure 5) inside bearings 6 that are integral with the frame of the machine. The first drawing roller 1 has, at one of its ends, a notched pinion 7 that is set in rotation via a notched belt 8, itself driven by a notched pinion 9 that is driven in rotation by a motor 10, via a kinematic chain (not shown). According to the invention, one of the drawing rollers 1 is driven in rotation by a notched belt 8 meshing with a pinion 7 that is integral with this first drawing roller 1, and the other drawing roller 2 is driven in rotation by a friction device. According to a first embodiment of the invention, and as shown in Figures. 1, 2 and 4 of the accompanying drawings, the friction device is in the form of a belt 12 without notches, setting in rotation a smooth pulley 11 that is integral with the second drawing roller 2. Thus, as the driving produced by the cooperation of a belt 12 without notches with a smooth pulley 11 is not completely positive, slight shifts of the one on the other are allowed and absorbed by the belt 12 without notches, and not by the covering of the pressure roller 3. The dimensions and the characteristics of the belt 12 without notches and the pulley 11 are determined in such a way that the drawing roller or rollers 2 is/are driven in an almost positive manner, i.e. such that, as soon as there is a difference in the peripheral speed of one of the drawing rollers 1 relative to the other 2 or the pressure roller 3, it is the belt 12 itself, and not the covering of the pressure roller 3, that slides over the pulley 11 and absorbs the difference in speed. The second drawing roller 2 has, at one of its ends, a pulley 11, which is preferably smooth and has a rounded rim, and which is set in rotation via a belt without notches, preferably a flat belt 12, itself driven by an intermediate pulley 13 that is mounted on an intermediate shaft 14. An intermediate notched pinion 15, which is driven in rotation by the notched belt 8, is mounted on this same intermediate shaft 14. The motor 10 thus drives in a positive manner without the possibility of the first drawing roller 1 sliding, while the second drawing roller 2 is driven by the friction device, which comprises the smooth pulleys 11 and 13 and the belt 12 without notches. The friction device is activated as soon as there is a slight difference in peripheral speed between the pressure roller 3 and the second drawing roller 2, allowing the belt 12 without notches to slide over one of the smooth pulleys 11 or 13. The belt 12 without notches consequently absorbs the sliding energy caused by slight differences in speed between one member and the other, the coating of the pressure roller 3 thus being preserved. Figure 4 of the accompanying drawings is a lateral elevation of a draw frame according to the invention. The tension of the belt 12 without notches may be adjusted by modifying the distance between the shafts of the smooth pulleys 11 and 13. For this purpose, the smooth pulley 13 is integral with the shaft 14, which is mounted on rolling bearings inside a bearing 20 that is articulated about an articulation shaft 21. The articulated bearing 20 may oscillate about the articulation shaft 21 and move relative to the frame of the machine, so as to modify the distance between the shaft of the smooth pulley 13 and that of the smooth pulley 11. A locking means 22, such as a screw and nut assembly, allows the bearing 20 to maintain a stable position relative to the frame of the machine. The tension of the notched belt 8 may also be adjusted by means of a tension device 23, the position of which may be modified relative to the frame of the machine. In order to ensure that the friction device operates correctly, the tension of the belt 12 without notches is adjusted first, then that of the notched belt 8. According to another variation of the invention, not shown in the accompanying drawings, the belt 12 without notches may also be driven directly via the calender roller 16, the intermediate pulley 13 then being mounted on the shaft of said calender roller 16, and said belt 12 without notches being subjected to tension via a tensioning wheel located on the course of said belt. In an embodiment of this type, the bearing 20, the articulation 21 and the locking means 22 are dispensed with. According to another variation of the invention, the friction device may be formed by the contact between the pressure roller 3 and the drawing rollers 1 and 2 (Figure 3). In this case, the first drawing roller 1 is set in non-slip rotation via a notched belt 8 and a notched pinion 7 that is integral with the drawing roller 1. The notched belt 8 cooperates with the notched pinion 9, as indicated above. The first drawing roller 1 transmits its rotational movement to the pressure roller 3 by surface contact. Said pressure roller 3 then transmits the rotational movement to the second drawing roller 2, also by surface contact. The second drawing roller 2 thus acquires the same peripheral speed as that of the pressure roller 3. According to another characteristic of the invention, and as shown in Figure 5 of the accompanying drawings, at least one of the rollers forming the draw frame is mounted on bearings 6 with removable caps, in order to allow said drawing roller to be dismantled and reassembled. For this purpose, according to another characteristic of the invention, each bearing 6 comprises a support 24a that is integral with the frame of the machine and a removable cap 24b. The support 24a and the removable cap 24b each has a semi-cylindrical roller bearing seat that is adjusted to the outside diameter of the roller bearing 5. This allows the drawing rollers 1 and 2 to be dismantled and reassembled quickly and easily if they have become worn or deformed, without having to remove them axially. In the current state of the art, if there are lubricated housings, the drawing rollers have to be removed axially from their bearings after said lubricated housings have been dismantled. This time-consuming and tedious process is essential if the drawing rollers have become worn or bent. If the removable cap 24b is detached from its support 24a, the drawing roller 1 or 2 may be removed radially with the corresponding rolling bearings 5. This simplifies the process of replacing the drawing rollers and reduces machine down times. According to another characteristic of the invention, if the textile machine is equipped with a calender roller 16 cooperating with a pressure roller 18, the notched belt 8 also meshes with a notched pinion 17 mounted at one end of said calender roller 16. A calender roller 16 of this type, which is helically fluted, is mounted on rolling bearings inside bearings that are integral with the frame of the machine, in the same way as the drawing rollers 1 and 2. The pressure roller 18, which is pressed against the calender roller 16, acquires the same peripheral speed as that of the calender roller 16. The peripheral speed of the calender roller 16 must be adjustable, relative to that of the draw frame, as a function of the quality of the textile material that the machine has to work. In some cases, the textile material must be more or less tightened, at times even slackened, between the draw frame and the calender roller. The tension, i.e. the peripheral speed ratio of the calender roller relative to the draw frame, may be modified by changing the notched belt 17. The precision of this adjustment is a function of the number of teeth of the pinion 17. According to another characteristic of the invention, and as shown in Figure 2 of the accompanying drawings, if the textile machine is equipped with a calender roller 16 cooperating with a pressure roller 18, the calender roller 16 is driven by friction, by the provision, at one of its ends, of a smooth pulley 19 driven in rotation by the belt 12 without notches. In this case, the tension, i.e. the peripheral speed ratio of the calender roller 16 relative to the draw frame, may also be modified by changing the smooth pulley 19. This adjustment is more precise, as it is dependent on the diameter of the smooth pulley 19, and not of an integer of teeth. According to another characteristic of the invention, not shown in the accompanying drawings, if the textile machine does not have a calender roller, the notched belt 8 cooperates with a notched pinion 17 that is mounted so as to rotate freely in a bearing on the frame of the machine, in an off-centre position relative to a straight line connecting the shafts of the smooth pulleys 11 and 13. The notched belt 8 is thus compelled to follow an identical course to that which it would take if the machine were equipped with a calender roller. The invention allows a novel draw frame to be produced less expensively than current frames. Moreover, a frame of this type does not require maintenance, and is not subject to leakages of lubricant. Furthermore, it allows the diameters of the pulleys and the rollers to be selected freely, so that they may be adapted precisely to the desired peripheral speed, and not as a function of the ratio of the numbers of teeth. Finally, the coverings of the pressure rollers are provided, and said draw frame does not cause said coverings to pulsate in a way that has, at times, led to textile imperfections in ribbons or roves. It will also be noted that the maximum temperature reached during operation by the moving members of the draw frame according to the invention is much lower than that of previously known devices: Damaged drawing rollers take less time to replace, resulting in improved efficiency of the textile machine. Furthermore, a draw frame of mis type allows production speeds, and therefore the capacity of the machine, to be increased. The invention is not, of course, limited to the embodiments described and illustrated in the accompanying drawings. Modifications are possible, in particular with regard to the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention. We claim: 1. Device for controlling a line of drawing rollers of a textile machine comprising two drawing rollers (1 and 2) mounted on bearings (6) and a pressure roller (3), which is pressed against the two drawing rollers (1 and 2), and optionally a calender roller (16) cooperating with a pressure roller (18), characterized in that one of the drawing rollers (1) is driven in rotation by a notched belt (8) meshing with a pinion (7) that is integral with the first drawing roller (1), and the other roller (2) is driven in rotation by a friction device. 2. Device as claimed in claim 1, wherein the friction device is in the form of a belt (12) without notches, driving in rotation a smooth pulley (11) that is integral with the second drawing roller (2). 3. Device as claimed in claims 1 and 2, wherein the second drawing roller (2) has, at one of its ends, a pulley (11), which is preferably smooth and has a rounded rim, and which is set in rotation via a belt without notches, preferably a flat belt (12), itself driven by an intermediate pulley (13) that is mounted on an intermediate shaft (14). 4. Device as claimed in claim 3, wherein an intermediate notched pinion (15), which is driven in rotation by the notched belt (8), is mounted on the intermediate shaft (14). 5. Device as claimed in claim 3, wherein the smooth pulley (13) is integral with the shaft (14), which is mounted on rolling bearings inside a bearing (20) that is articulated about an articulation shaft (21). 6. Device as claimed in claims 1, 3 and 4, wherein the tension of the notched belt (8) may be adjusted by means of a tension device (23), the position of which may be modified relative to the frame of the machine. 7. Device as claimed in claims 1 and 2, wherein if the textile machine is equipped with a calender roller (16) cooperating with a pressure roller (18), the belt (12) without notches is driven directly via the calender roller (16), the intermediate pulley (13) being mounted on the shaft of said calender roller (16), and said belt (12) without notches being subjected to tension via a tensioning wheel located on the course of said belt. 8. Device as claimed in claim .1, wherein the friction device is formed by the contact between the pressure roller (3) and the drawing rollers (1 and 2). 9. Device as claimed in claim 1, wherein at least one of the rollers forming the draw frame is mounted on bearings (6) with removable caps. 10. Device as claimed in claim 9, wherein each bearing (6) comprises a support (24a) that is integral with the frame of the machine and a removable cap (24b). 11. Device as claimed in claim 1, wherein if the textile machine is equipped with a calender roller (16) cooperating with a pressure roller (18), the notched belt (8) also meshes with a notched pinion (17) mounted at one end of said calender roller (16). 12. Device as claimed in claim 1, wherein if the textile machine is equipped with a calender roller (16) cooperating with a pressure roller (18), the calender roller (16) is driven by friction, by the provision, at one of its ends, of a smooth pulley (19) driven in rotation by the belt (12) without notches. 13. Device as claimed in claim 1, wherein if the textile machine does not have a calender roller, the notched belt (8) cooperates with a notched pinion (17) that is mounted so as to rotate freely in a bearing on the frame of the machine, in an off-centre position relative to a straight line connecting the shafts of the smooth pulleys (11 and 13). 14. Method for controlling a line of drawing rollers of a textile machine carried out by the device as claimed in claim 1, comprising two drawing rollers (1 and 2) mounted on bearings (6) and a pressure roller (3), which is pressed against the two drawing rollers (1 and 2), and optionally a calender roller (16) cooperating with a pressure roller (18), characterized in that it substantially consists in driving one of the drawing rollers (1) in non-slip rotation and in driving the other drawing roller (2) in rotation by friction.

Documents:

1360-DELNP-2004-Abstract-(19-06-2009).pdf

1360-DELNP-2004-Abstract-(19-10-2011).pdf

1360-delnp-2004-abstract.pdf

1360-DELNP-2004-Claims-(19-06-2009).pdf

1360-DELNP-2004-Claims-(19-10-2011).pdf

1360-delnp-2004-claims.pdf

1360-delnp-2004-Correspondence Others-(02-08-2012).pdf

1360-DELNP-2004-Correspondence Others-(19-10-2011).pdf

1360-DELNP-2004-Correspondence-Others-(19-06-2009).pdf

1360-delnp-2004-correspondence-others.pdf

1360-DELNP-2004-Description (Complete)-(19-06-2009).pdf

1360-DELNP-2004-Description (Complete)-(19-10-2011).pdf

1360-delnp-2004-description (complete).pdf

1360-delnp-2004-Drawings-(02-08-2012).pdf

1360-DELNP-2004-Drawings-(19-06-2009).pdf

1360-DELNP-2004-Drawings-(19-10-2011).pdf

1360-delnp-2004-drawings.pdf

1360-DELNP-2004-Form-1-(19-10-2011).pdf

1360-delnp-2004-form-1.pdf

1360-delnp-2004-form-18.pdf

1360-DELNP-2004-Form-2-(19-06-2009).pdf

1360-DELNP-2004-Form-2-(19-10-2011).pdf

1360-delnp-2004-form-2.pdf

1360-DELNP-2004-Form-3-(19-06-2009).pdf

1360-delnp-2004-form-3.pdf

1360-delnp-2004-form-5.pdf

1360-DELNP-2004-GPA-(19-06-2009).pdf

1360-delnp-2004-gpa.pdf

1360-DELNP-2004-Others-Documents-(19-06-2009).pdf

1360-delnp-2004-pct-210.pdf

1360-DELNP-2004-Petition-137-(19-06-2009).pdf

1360-DELNP-2004-Petition-138-(19-06-2009).pdf

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