Title of Invention

A FIXTURE FOR CLAMPING ROLLERS

Abstract

The present invention relates to a fixture 20 for clamping rollers 11, 13, 15, 16 which, by means of a holding element 26, are held on a pressure application device 17, whereby the pressure application device is a pressure arm 17 of a drafting unit, and which is pressed against a counter element 14 for creating nip lines, wherein the holding element 26, for changing the position of the nip lines, is adjustably attached on the pressure application device 17, the clamping rollers 11, 13, 15, 16, for changing the position of the nip lines, are adjustably attached on the holding element 26, characterized in that, as holding element, a clamp strap 26 is provided which is divided into two parts 27, 28, one of which 27 is attached on the pressure application device 17 and one of which, the other part 28, comprises mounting means for the clamping rollers 16, and the two parts 27, 28 of the clamp strap 26 are connectable ":lith each other in at least two different positions, wherein one part 27 of the clamp strap 26 is held swivable and with an adjustable contact pressure.

Full Text

Fixture for clamping rollers The invention relates to a fixture for clamping rollers which, by means of a holding element, are held on a pressure application device and which can be pressed against a counter element for creating nip lines. Clamping rollers held in such a way are required in particular in connection with the so-called condense spinning, whereat the roving, which leaves a drafting unit, first goes through a condensing zone and is then twisted into a thread. In the direction towards the component generating the spinning twist, in particular a ring spinning device, the condensing zone is limited by means of a clamping roller and a counter element which, together, form a nip line which prevents a return movement of the spinning twist into the compression zone. For condense spinning several different methods and devices are known, where the counter element for example is a perforated drum being acted upon with suction air (DE 44 26 278 A1, DE 44 26 249 A1 EP 0 947 614 A2), or a profile, on which slides an air-permeable tape (DE 198 37 179 A1) or a roller, across which runs a perforated tape (DE 197 41 441 CI). It is the object of the present invention to provide a fixture of the above-mentioned type, which allows the changing of the clamping positions. This task is solved with a first embodiment in such a way, in that the holding element for changing the position of the nip lines is adjustably attached on the pressure application device. With a second embodiment the task is solved in such a way, in that for changing the position of the nip lines the clamping roller is adjustably attached on the holding element. With drafting units for ring spinning frames an arrangement is made in that the pressure application device is a pressure arm of a drafting unit In a further embodiment of the invention, a clamp strap is being provided as a holding element which is divided into two parts, whereat one of said parts is attached on the pressure application device and the other part comprises a mounting for the clamping rollers and that the two parts of the clamp strap are connectable with one another in adjustable positions. Thereby it is favourable if in an arrangement of the invention that one part of the clamp strap is being provided as a swivable part and that it is held with an adjustable contact pressure. Due to the division of the clamp strap into a part for mounting the swivelling axis and into a part for mounting the clamping rollers, the possibility results to interconnect these two parts in different positions so that thereby the distance between the nip line of the pair of outlet rollers of the drafting unit and the nip line formed by the clamping roller can be changed. In an embodiment of the invention it is provided for, that the two parts of the clamp strap are furnished with such profiles that guide one another. This way it is sufficient to attach the two parts to one another for example only with one screw since the two parts cannot turn themselves relatively to each other due to the profiled shape. In a further embodiment of the invention it is provided for, that the clamp strap, together with a supplementary arm, forms a structural unit which is attachable on the pressure arm of the drafting unit. By means of the additional structural unit a conventional drafting unit can be converted in a relatively simple way into a drafting unit that is suitable for condense spinning. Thereby it is suitable if the loaded spring is integrated into the structural unit. Thus no changes are required within the remaining drafting unit. In a further favourable embodiment it is provided for, that between the clamp strap and the supplementary arm a pre-loadable pressure spring is arranged. Thus it is possible to accurately adjust the load force, by which the clamping roller is pressed against the counter elements, to predetermined values. Thereby it is further favourable that in a further embodiment the maximum swivelling path of the clamp strap is limited by means of a stop relative to the supplementary arm. Since the path required for the functioning of the clamping roller is relatively short, it can thus be made sure that the pre-mounted unit, even if the clamping rollers do not rest against their counter element, is essentially of the same shape as during operation. In a further embodiment of the invention it is provided for, that the supplementary arm is covered with a cover. This cover can be formed for example as a handle, by means of which the pressure arm can be taken when opening the drafting unit. In a further embodiment of the invention it is provided for, that the supplementary arm or the cover is arranged as cleaning roller holders. Thus a further function can be allocated to the supplementary arm or also to the cover attached to it. Further advantages and features of the invention result from the following description of the types of embodiments represented in the drawing, wherein Fig. 1 shows a schematic side view of a drafting unit with a pneumatic condensing device, Fig. 2 a perspective view of a fixture for clamping rollers of the condensing device, and Fig. 3 a longitudinal section through the fixture of figure 2. The drafting unit shown schematically in figure 1 is combined with a pneumatic condensing device. The drafting unit comprises a pair of feed rollers with a bottom cylinder 10 and a top cylinder 11 extending in longitudinal direction of the frame, a pair of centre rollers with a bottom cylinder 12 and a top cylinder 13 extending in longitudinal direction of the frame, as well as a pair of outlet rollers with a bottom cylinder 14 and a top cylinder 15. In the drafting unit which is provided for a ring spinning frame in particular, but which can also for example be applied with a flyer, a not shown roving is drawn to a desired refined condition, in that the bottom cylinder 12 and the top cylinder 13 run faster than the bottom cylinder 10 and the top cylinder 11 and in that the bottom cylinder 14 and the top cylinder 15 again run faster than the bottom cylinder 12 and the top cylinder 13. Before the drawn roving leaves the drafting unit, pneumatic condensing takes place in the zone of the surface of the bottom cylinder 14 following the top cylinder 15. For this, the bottom cylinder 14 is designed as a perforated cylinder, as this is known for example from the DE 44 26 249 A1. Within the perforated cylinder a suction insert is provided which is connected to a vacuum source and which is provided with a suction slot directed to the zone after the top cylinder, said suction slot preferably running slantedly towards the circumferential direction. To the circumference of the bottom cylinder 14 a clamping roller 16 is arranged furthermore forming a nip line with the bottom cylinder 14. This nip line prevents a spinning twist given to the roving within the zone between the top cylinder 15 and the clamping roller 16, by a not shown twisting means, for example a ring spinning device, from running back, i.e. into the range of the pneumatic condensing zone. The bottom cylinders 10 and 12 as well as the bottom cylinder 14, designed as perforated drums, are driven in a not further shown way. The top cylinders 11, 13, 15 and the clamping roller 16 are each driven by means of friction through the driven bottom cylinders 10, 12 and the bottom cylinder 14. The top cylinders 11, 13, 15 and the clamping roller 16 are provided with a rubber-elastic coat. Usually drafting units are designed as twin aggregates, i.e. the top cylinders 11, 13, 15 and the damping rollers 16 are twin rollers whose shafts are held by a pressure arm 17. The pressure arm 17 is swivable around an axis 18 so that the top cylinders 11, 13, 15 and the clamping rollers 16 can be lifted off from the bottom cylinders 10, 12 and the bottom cylinder 14 in order to open the drafting unit. The top cylinders 11, 13, 15 are loaded in the known manner with loaded springs which determine the contact pressure onto the bottom cylinders 10, 12 and the bottom cylinder 14, if the pressure arm 17 is held in the operating position by means of a locking lever 19 as is shown in figure 1. For the clamping roller 16, i.e. usually for a pair of clamping rollers, their own fixture 20 is provided which is attached to the pressure arm 17. This fixture 20 comprises a supplementary arm 21, u-shaped in the cross section, which embraces the end section of the pressure arm 17 from above and which is fastened to the pressure arm by means of a screw 22 and a threaded holding disk 23. On the supplementary arm 21 a threaded sleeve 25 is mounted, by means of two screws 24 which serves as pivoting axis for a clamp strap 26. The clamp strap 26 consists of two parts, that is, a swivel lever 27 which is mounted by means of the threaded sleeve 25 and a pressure saddle 28 attached thereto. The swivel lever 27 with one arm faces the transverse web of the u-shaped supplementary arm 21 and with this forms a stop means which limits the swivel motion of the clamp strap 26. The swivel lever 27 is provided with a mounting section 30 for a pressure spring 31 which pushes against a threaded stud 32 screwed into the mounting 30 and the transverse web of the supplementary arm 21. By adjusting the threaded stud 32, the pressure spring 31 which serves as loaded spring for the clamping roller 16 can be pre-loaded to a desired force. The pressure saddle attached to the swivel lever 27 is furnished with a spring clip 32, with which the axis of a pair of clamping rollers 16 is being secured in the pressure saddle 28. The pressure saddle 28 comprises an essentially u-shaped cross section, whereby the transverse web connecting the two shanks is provided with a longitudinal profile in the form of a prism or similar. With this longitudinal profile the pressure saddle 28 is being guided in a negative correlating profile of the swivel lever 27. The pressure saddle 28 is located in a given position by means of a screw 34 being screwed into a tapped hole of the swivel yoke 27. As can be seen from figure 3, the swivel yoke 27 is provided with at least one further tapped hole 35, so that the pressure saddle 28 can be attached in at least one further position to the swivelling yoke 27. This way it is possible to change the position of the clamping rollers 16 towards the double arrow A of figure 1 relative to the position of the pressure rollers 15. In the closed position of the drafting unit which is illustrated in figure 1, the arm of the swivel lever 27 which carries the pressure saddle 28, runs essentially parallel to a tangent in relation to the bottom cylinder 14, so that the pressure saddle 28 is adjustable nearly tangentially to this bottom cylinder 14. In order to obtain the correct contact pressure force for the clamping rollers 16 in each position, the threaded stud 32 is adjusted accordingly. In the exemplified embodiment it is provided for, that the pressure saddle 28 and thus the clamping rollers 16 can be adjusted in only two given positions in relation to the bottom cylinder 14. Determining fixed positions has the advantage that while adjusting a frame, the possibilities of errors are relatively low. However, it is to be considered that a ring spinning frame comprises 500 to 600 spinning places on each machine side which are all to be adjusted the same way if possible. It is, however, also possible to mount the pressure saddle steplessly adjustable onto the swivel lever 27 as for example an oblong hole is provided in the transverse web of the pressure saddle 28. In this case it is suitable, while adjusting the pressure saddles 28 of all spinning places, to provide suitable templates. The supplementary arm 21 is covered with a cover 36 which preferably is made of plastic. This cover 36 serves on one hand as a gripping part 37 at which the unit, consisting of the pressure arm 17 and supplementary arm 21, can be gripped and lifted to open the drafting unit. Beyond that the cover 36 furthermore forms a mounting means for a not illustrated cleaning roller. If the fixture 20 for the clamping rollers 16 is not used in connection with a drafting unit according to figure 1, but with a drafting unit and a succeeding condensing device which is provided with an own bottom cylinder, then the fixture 20 can principally be laid out alike. The arm of the swivel lever 27, to which the pressure saddle 28 is fastened, is then aligned in such a way that it is adjusted parallel to a tangent to this bottom cylinder. With a modified form of an embodiment it is provided for to do without the supplementary arm, so that the clamp strap is fastened directly onto the pressure arm 17. With a further modification of the embodiment it is provided for, that the clamp strap is adjustably attached, as a whole structural unit, in the pressure arm 17 or in the supplementary arm 21 in order to change the position of the nip lines. Beyond that other solutions are also conceivable, for example for holding the pressure roller 15 and the clamping rollers 16 by means of a jack mounted on a pressure arm or similar, whereby the clamping rollers 16 are then attached adjustably on the jack. Claims 1. Fixture for clamping rollers which, by means of a holding element, are held on a pressure application device and which can be pressed against a counter element for creating nip lines, characterized in that the holding element, for changing the position of the nip lines, is adjustably attached on the pressure application device. 2. Fixture for clamping rollers which, by means of a holding element, are held on a pressure application device and which can be pressed against a counter element for creating nip lines, characterized in that the clamping rollers, for changing the position of the nip lines, are adjustably attached on the holding element (26). 3. Fixture according to claims 1 or 2, characterized in that the pressure application device is a pressure arm (17) of a drafting unit. 4. Fixture according to claims 2 or 3, characterized in that as holding element, a clamp strap (26) is provided which is divided into two parts (27, 28), of which a part (27) is attached on the pressure application device (17) and of which an other part (28) comprises a mounting means for the clamping rollers (16) and that the two parts (27, 28) of the clamp strap (26) are connectable with one another in at least two different positions. 5. Fixture according to claim 4, characterized in that the one part (27) of the clamp strap (26) is held swivable. 6. Fixture according to claims 4 or 5, characterized in that the two parts (27, 28) of the clamp strap (26) are furnished with such profiles so that they guide one another. 7. Fixture according to one of the claims 4 to 6, characterized in that the clamp strap (26) together with a supplementary arm (21) is formed as a structural unit which is attachable on the pressure application device (17). 8. Fixture according to claim 7, characterized in that a pressure spring (31) is integrated into the unit. 9. Fixture according to claim 8, characterized in that between the clamp strap (26) and the supplementary arm (21) a pre-loadable pressure spring (31) is being arranged. 10. Fixture according to one of the claims 7 to 9, characterized in that the maximum swivelling path of the clamp strap (26), in relation to the supplementary arm (21), is limited by means of a stop element. 11. Fixture according to one of the claims 7 to 10, characterized in that the supplementary arm (21) comprises a u-shaped cross section. 12. Fixture according to one of the claims 7 to 11, characterized in that the supplementary arm (21) is covered with a cover (36). 13. Fixture according to one of the claims 7 to 12, characterized in that the supplementary arm (21) or the cover (36) are arranged as a holder for the cleaning roller. 14. Fixture for clamping rollers substantially as herein described with reference to the accompanying drawings. Dated this 09 day of September 2002 13.08.02 We/ps-2927A/E Summary For clamping rollers (16) loaded with a pressure spring (31), a fixture (20) is provided which is attachable on a pressure arm (17) of a drafting unit and which offers a possibility to change the position and contact pressure of the clamping rollers. Fig. 1.

Documents:

0672-mas-2002 abstract-duplicate.pdf

0672-mas-2002 claims-duplicate.pdf

0672-mas-2002 descripition(completed)-duplicate.pdf

0672-mas-2002 drawings-duplicate.pdf

672-mas-2002-claims .pdf

672-mas-2002-correspondence others.pdf

672-mas-2002-correspondence po.pdf

672-mas-2002-description complete.pdf

672-mas-2002-drawings.pdf

672-mas-2002-form 1.pdf

672-mas-2002-form 18.pdf

672-mas-2002-form 3.pdf