Title of Invention

SPINNING FRAME WITH A DRAFTING UNIT AT WHOSE OUTLET A SUCTION DEVICE WITH A TUBE IS ARRANGED

Abstract

SPINNING FRAME WITH A DRAFTING UNIT AT WHOSE OUTLET A SUCTION DEVICE WITH A TUBE IS ARRANGED In a spinning frame with a drafting unit at whose outlet a suction device with a tube (30) is being arranged wherefrom an opening (dl) of the tube is directed towards a yarn (12b) leaving the drafting unit, the opening (dl) at the side facing a bottom roller (28) of the drafting unit is being provided with an edge which runs parallel to the axis of the bottom roller, while the side of the opening (dl) opposing said edge, is converging to form a peak. The outline of the opening (dl) is preferably triangular or pentagonal. It is sized at least that large that a slightly twisted fibre band with a circular cross section of 5 mm diameter can be led into the opening (dl) and thus into the tube. With a tube in the suction device being configured in the described way the operating behaviour of a spinning frame can be improved. (Figure 1)

Full Text

The present invention relates to a spinning frame with a drafting unit at whose outlet a suction device with a tube is arranged. In the German patent application DE 37 08 113 a suction device for broken threads on a spinning frame is being disclosed, with a tube which conically diverges in flowing direction of the suctioned air, whereat the plane of the suction opening of said tube is basically being positioned parallel to the thread path. The opening of the tube is shown below the axis of a bottom roller of the drafting unit at a distance from the thread which amounts to about D/2 of the bottom roller. In order to be able to securely suck off a broken thread or a fibre band respectively which has hardly been twisted because of an initial thread break, a sufficiently high flowing speed of the suction air has to be provided within the tube. Therefrom results a high energy consumption of the spinning frame. It is the object of the present invention to provide a tube for a suction device which even at relatively low subpressure within the suction system securely picks up a fibre band or a thread respectively. This task is being solved by a suction device of the present invention as described herein. Accordingly the present invention provides a spinning frame with a drafting unit at whose outlet a suction device with a tube is arranged wherefrom an opening of the tube is directed toward a yarn leaving the drafting unit, characterised in that the opening at the side facing a bottom roller of the drafting unit is being provided with an edge which runs parallel to the axis of the bottom roller, and that the side of the opening opposing said edge, is converging to form a peak. The spinning frame being designed according to the invention consists of a drafting unit with a suction device at its outlet in form of a tube, whose suction opening is being directed towards a yam leaving the drafting unit. The opening, at the side facing a bottom roller of the drafting unit is being provided with an edge which runs parallel to the axis of the bottom roller, while the side of the opening opposing said edge, is converging to a peak. The opening has preferably the outline of a triangle or pentagon, whereat the comers of the opening, which lay in the crossing points of the merging edges of the opening are being rounded. The edge of the opening facing the bottom roller is at least of a length that corresponds with the stroke of the traversing device in the drafting unit. The opening is sized at least that large that a the press^rejoMr_QrJhe.to£jol|er respectively, being arranged to the bottom roller, can also be cleaned sufficiently under the effect of suction air. At a given subpressure in a suction channel a comparatively high inlet speed of the air flow can be achieved with the tube being dimensioned according to the invention and thus a sufficient fibre suction force being in compliance with the respective requirements. The fibre suction force reaches its highest value just at the point where loose fibres develop. In the following the invention is being described in detail according to the accompanying drawing, wherein show: fig. 1 a schematic arrangement of a drafting unit of a spinning frame with the suction device fig. 2 a view onto the tube in its longitudinal direction fig. 3 a detail of the opening. From a roller pair, consisting of a bottom roller 28 and a top roller 26 being pressed against it, a fibre band 12a is being drawn in the direction of a not further shown twisting and winding device. After leaving the roller pairs 26,28 the fibre band 12a has been drawn and is then being twisted to a yarn 12b. A further roller pair, consisting of a further bottom roller 16 and a further top roller 14 is being enveloped by a bottom tape 20 and a top tape 18 respectively, which tapes (aprons) are being guided by a lower deflecting bridge 24 and an upper cradle 22. When the yarn 12b breaks the flow of material from the drafting unit to the winding device is being interrupted, therefore the additionally supplied fibre band 12a from the outlet of the roller pair, that is from between the bottom roller 28 and the top roller 26, has to be led away, so that the operation of the neighbouring spinning units are not being disturbed. For this purpose there is a fibre or thread suction device being provided on the spinning frame below the drafting unit. As part of said suction device a channel 32 and single tube 30 are being shown. Near the bottom roller 28 the tube is being provided with an opening d1. At the other end the tube has a hole d2 at the partially shown channel 32. A projection or engaging element 30a at the tube 30 allow the fastening of the tube on a stationary part within the spinning frame, in that the engaging elements 30a or rim 30b are being locked within a respective recess. The tube has a length c and measured on a plane F at the opening d1 has a basic width g and the height h. The opening d1 is shown in a view at right angle onto the plane F. Opposite of the edge with the basic width g the opening d1 converges into a peak. The shape of the opening is, as indicated in figure 2, either triangular (thin line) or has the shape of a pentagon (thicker line). The opening is to be of such a size that a roving, shown in figure 2 in circular shape, or a fibre bundle of the respective diameter, can enter the tube 30 through said opening d1 without being deformed. The opening d1 laying on the plane F includes an angle of a = 100° to 150° with the axis of the tube 30 and an angle of b = 30° to 50° with the yarn 12b. Within a shoulder portion in downward direction of a collar 30b a seal 30c is being applied to seal the inside of the tube 30 against the surrounding air. The position of the tube 30 according to figure 2 is being defined by two engaging elements 30a which can be fastened and locked against turning on at least two holders in a stationary part of the spinning frame. According to figure 3 the opening d1 is preferably being formed with round corners. slightly twisted fibre band or roving having a circular cross section of 5 mm in diameter, can enter the opening and thus the tube without deformation. The opening lays on a plane which runs parallel to the axis in the bottom roller and which is inclined at an angle between 30 to 50° in relation to the yarn being drawn from the drafting unit. Furthermore the plane of the opening preferably includes in relation to the axis of the tube an angel of 100 to 150°. The opening should have a cross sectional surface of at least 30 mm2, but less than 70 mm2, so that the air consumption remains limited. To a tangent on a bottom roller at the clamping point with a pertaining top roller the plane of the opening includes an angle of 20 to 40°. The distance of the edge of the opening being closest to the bottom roller amounts to between 1 and 3 mm. The side of the opening opposing the bottom roller and which converges to form a peak is to have a distance of between 3 and 10 mm towards the thread path of the yarn which is being drawn from the drafting unit. With a tube according to the invention the operating behaviour of a spinning frame, a ring spinning frame in particular can be considerably improved. Contamination and clogging within the tube are being avoided by the configuration according to the claims. Also the tendency of winding of the two bottom rollers in the drafting unit can be reduced considerably, as well as the rate of thread breaks. Preferably the body of the tube is being formed with a constant conicity and a circular cross section. The inlet opening directed towards the bottom roller preferably includes an angle of 45° towards the thread path. The quantity of suction air and thus the energy consumption of the spinning frame can be achieved by a cross section of the opening which is as small as possible. The opening is being sized so that a nontwisted roving and small fibre flakes, coming from the drafting unit 12 are being suctioned without deformation. The width of the suction opening of the tube has to correspond with the thread traversing stroke. The basically triangular or pentagonal shape of the opening results from the requirement that the opening has to be as close to the bottom roller as possible, further by the necessity of a minimum width as mentioned and an inner clearance of at least 4 mm. The slanted opening of the tube, that is its angular shape of approximately 45° in relation to the thread moving path takes into consideration the fall-off direction of the fibres during a thread break. Due to the slanted opening WE CLAIM : 1. Spinning frame with a drafting unit at whose outlet a suction device with a tube (30) is arranged wherefrom an opening (dl) of the tube (30) is directed toward a yarn (12b) leaving the drafting unit, characterised in that the opening (dl) at the side facing a bottom roller (28) of the drafting unit is being provided with an edge which runs parallel to the axis of the bottom roller (28), and that the side of the opening (dl) opposing said edge, is converging to form a peak. 2. Device as claimed in claim 1, wherein the opening (dl) has the outline of a triangle or a pentagon. 3. Device as claimed in claim 1 or 2, wherein the comers of the opening (dl) which lay in the crossing points of merging edges of the opening are being rounded. 4. Device as claimed in any one of the claims 1 to 3, wherein the edge of the opening (dl) facing the bottom roller (28) is at least of a size that corresponds with the stroke of a traversing device in the drafting unit. 5. Device as claimed in any one of the claims 1 to 4, wherein the opening (dl) is sized at least that large, that a slightly twisted fibre band or roving respectively, having a circular cross section of 5 mm diameter, can enter the opening (dl) and thus the tube (30) without deformation. 6. Device as claimed in any one of the claims 1 to 5, wherein the opening (dl) lays on a plane (F) which runs parallel to the axis of the bottom roller (28) and which is inclined at an angle b = 30° to 50 ° in relation to the yarn (12b) being led from the drafting unit, from the bottom roller (28) respectively in the direction of towards a twisting and winding device. 7. Device as claimed in any one of the claims 1 to 6, wherein the opening (dl) lays on a plane (F) which in relation to the axis of the tube (30) includes)an angle of a =100° to 150°. 8. Device as claimed in any one of the claims 1 to 7, wherein the tube (30) from the opening (dl) up to an opening (d2) is being conically enlarged and whereto it extends without changing direction. 9. Device as claimed in any one of the claims 1 to 8, wherein the tube (30) is being provided with two engaging elements (30a) by which it can be fastened and locked against turning on at least 2 holders in a stationary part of the spinning frame. 10. Device as claimed in any one of the claims 1 to 9, wherein the opening (dl) is being provided with a cross sectional surface of 20 to 70mm . 11. Device as claimed in any one of the claims 1 to 10, wherein the opening (dl) lays on a plane which includes an angle of 20° to 40° with a tangent on a bottom roller (28) at the clamping point with a pertaining top roller (26). 12. Device as claimed in any one of the claims 1 to 11, wherein the edge of the opening (dl) facing the bottom roller (28) has a distance to said bottom roller (28) of between 1 mm and 3 mm. 13. Device as claimed in any one of the claims 1 to 12, wherein the side of the opening (dl) opposing the bottom roller (28) and which converges to a peak, has a distance to the running path of a yarn (12b) of 3 mm to 10 mm. 14. Spinning frame with a drafting unit at whose outlet a suction device with a tube is arranged, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

236-mas-1999-abstract.pdf

236-mas-1999-claims.pdf

236-mas-1999-correspondence others.pdf

236-mas-1999-correspondence po.pdf

236-mas-1999-description complete.pdf

236-mas-1999-drawings.pdf

236-mas-1999-form 1.pdf

236-mas-1999-form 26.pdf

236-mas-1999-form 3.pdf

236-mas-1999-form 4.pdf

abs 0236-mas-1999 abstract.jpg