Title of Invention

SPINNING FRAME WITH PROGRESSIVELY ACTING DRAFTING UNIT

Abstract

In a spinning frame a drafting unit is being provided with at least a first roller pair (w1) and a second roller pair (w2) and with a bottom apron (14) and a top apron (12) respectively arranged in-between, which aprons are partially being guided by a deflecting bridge (18) and a cradle (16) between the roller pairs (w1 ,w2). On its way from the roller pair (w1) up to the roller pair (w2) a fibre band (10) is being drawn while it is being guided between the aprons (12,14), the cradle (16) and the deflecting bridge (18) respectively, on a basically S-shaped path, whereat in the first section S at least up to the turning point the arching of the fibre band (10), due to decreasing arch radii (r2,r3) on the fibre band (10) facing the side of the deflecting bridge, preferably increases progressively.

Full Text

The invention relates to a spinning frame with a drafting unit according to the preamble of the first claim. The patent literature describes drafting units for spinning frames, whereat the fibre band is being bent several times between two respective roller pairs. Partially the fibre band follows the course of the aprons (tapes) being pressed towards each other between deflecting elements for the tapes, which are arranged between roller pairs. With the multiple deflection it is intended to press the flbre band together, so that the fibres do not diverge too much during the drawing process and which allows a controlled guidance of the fibres with regard to the increase of speed. Corresponding publications are known from the patent applications EP 04450 361 and DE 43 44 319.2. It was found that with the conventional solutions satisfactory yarn qualities are not always being obtained, wherefrom the task resulted to further improve the guidance of the fibres during the drafting process. Said task is being solved by the object of the claims. By means of a spinning frame with the drafting unit according to the invention yams can be produced which are of higher quality than those yams being produced with conventional drafting unit components. The object of the invention is to provide a spinning frame with a drafting unit, comprising at least one first roller pair and a second roller pair, whereat each roller of the first pair is being enveloped by a bottom apron and a top apron respectively, which endless tapes (aprons) are being guided by a lower deflecting bridge, and an upper cradle respectively, thereby being in close contact to each other over a part of their path in the direction towards the second roller pair. Thereby an arched course results for a fibre band being led in-between the roller pairs and the aprons - respectively, whereat the side of the deflecting bridge facing the bottom apron and the cradle comprises at least 3 arched sections with different radii, said arched sections following each other in the running direction of the fibre band and which change from a first medium bend into a slight bend and from there over to a stronger bend. In relation to the distance between the pairs of rollers the deflecting radius of the deflecting bridge is at first approximately half the value of that distance, within the centre section of said bridge it takes on a value corresponding with that distance and within the end section, which is closest to the second roller pair, the radius amounts to at maximum half the distance of the roller pairs. The length of the deflecting bridge, as far as it determines the course of the fibre band, amounts to approximately half the distance of the roller pairs. The first arched section of the deflecting bridge, with the arching radius corresponding approximately half the distance of the roller pairs, extends in the running direction of the fibre band at maximum over half the length of the deflecting bridge, while the two following arched sections with the arching radii that become smaller, are within the middle section or the end section of the deflecting bridge, respectively. The diameter of the single rollers amounts up to 50 - 70 % the distance of the roller pairs. The end portion of the cradle is arranged as close to the second roller pair as possible, in such a way that it is being located between the end portion of the deflecting bridge with the third arched section and the second roller pair, so that preferably an s-shaped course for the fibre band results between the roller pairs. The deflecting bridge and the cradle are designed and arranged in such a way that between the bottom apron within the first arched section of the deflecting bridge and the top apron a gap is formed which gradually becomes smaller, so that the entering fibre band is being clamped. Within the following arched sections the surface pressure onto the fibre band increases gradually. This is best achieved in that the bend of the deflecting bridge in the second and third arched section increases progressively. During the drawing process of the fibre band it is important that at least within the area of the deflecting bridge said fibre band is always being guided on an arched course, whereat the bend should increase within a partial section of the deflecting bridge that is being located near the second roller pair. The arched section in the running direction of the fibre band at first have a relatively strong bend for entering the gap between the upper tape and the lower tape (apron). Within the second section of the deflecting bridge a relatively slight bend follows, with comparatively slight pressure onto the fibre band. In this section the fibres should be easier drawn due to the slighter clamping force, rather than within the following last section with a comparatively strong bend, with a smaller bending radius than in the first section or the inlet section of the deflecting bridge respectively. In the following the invention is being described in detail by way of the accompanying drawing. A fibre band 10 is led via a pair of rollers w through a drawing zone up to the first roller pair w1 and further to a second roller pair w2 whereafter the fibre band 10 is being led to a device for twisting and winding. Between the roller pairs w1 and w2 a deflecting bridge 18 and a cradle 16 inclining toward said bridge are being arranged, whereat the end portion of the cradle 16 facing the roller pair w2 projects into the zone between the deflecting bridge 18 and the roller pair w2. A roller each of the first roller pair w1 is being enveloped by a bottom apron 14 and a top apron 12 respectively, which aprons (tapes) are also being led over the only partially shown deflecting bridge 18 and the cradle 16 respectively. The aprons consist of endless tapes and are being put into motion by the roller pair w1, in order to transport the fibre band 10 from the roller pair w1 to the roller pair w2. As is shown in the schematic illustration, the fibre band 10 follows an s-shaped path, whereat the first bend of the S is being effected by the shape of the deflecting bridge 18 facing the cradle and the second bend of the S is being effected by the contour of the end portion of the mentioned cradle 16. The deflecting bridge 18, the pertaining lower apron 14 as well as the cradle 16 with the top apron as well as the roller pair w1 and w2 are illustrated in such a way that the aprons 12,14 and the fibre band 10 and the rollers of the roller pair w1 and w2 respectively, have an ample distance from each other. In a realistic layout of a drafting unit of a spinning frame the distances between the rollers w1 ,w2 and the aprons 14,12 are calculated in such a way that a clamping force is being applied onto the fibre band 10 in order to make an appropriate drawing process for the fibres of the fibre band 10 possible. According to the invention tine deflecting bridge 18 comprises at least three differently arched sections with the radii r1,r2,r3. The roller pair w1 and w2 are positioned at a distance s to each other. The ratio between the measurement s to the length u of the deflecting bridge 18 being effective with regard to the fibre band 10, measured in the direction of the contacting line of the clamping gap of the roller pair w1 and w2, is approximately 2:1 towards each other. The arch radii r1,r2,r3 are chosen in such a way that the first radius measures approximately half the size of the roller distance s while the radius r2 is approximately the same as the roller distance and the arch radius r3 measures only about one third of the roller distance s. The measurement of the diameter of the roller pairs w1 ,w2 in a preferred embodiment amounts to somewhat more than half the roller distance s/2. The following table lists the preferred dimensions of the described elements of the drafting units: The measurements for the example of a ring spinning frame are given in mm. Independently of the effective measurements (metric or other), the dimensions of the elements of the drafting unit can be indicated in relation to each other as follows: The effective dimensions can thus be calculated by substitution of any value for the roller distance s. WE CLAIM: 1. A spinning frame with a drafting unit, comprising at least a first roller pair (wl) and a second roller pair (w2), whereat each roller of the first pair (wl) is being enveloped by a bottom apron (14) and a top apron (12) respectively, which endless aprons are being guided by a lower deflecting bridge (18) and an upper cradle (16) respectively, thereby being at close contact to each other over a part of their path in the direction towards the second pair of roller (w2) in such a way that an arched course results for a fibre band (10) being led in between the pairs of rollers (wl,w2) and the aprons (12,14) respectively, characterised in that the side of the deflecting bridge (18) facing the bottom apron (14) and the cradle (16) comprises at least 3 arched zones with at least 3 different radii (rl,r2,r3), said ranges following each other in the running direction of the fibre band (10) and which in relation to the distance (s) between the pairs of rollers (wl,w2) are being provided with deflecting radii. 2. The spiiming frame according to claim 1, wherein the length (u) of the zone of the deflecting bridge (18) with the three differently arched zones (rl,r2,r3) in the direction towards the contacting line of the clamping gap of the roller pairs (wl,w2), in relation to the distance (s) lays within the following value range: 3. The spinning frame according to claim 2, wherein the first arched section with the radius (rl) seen in the running direction of the fibre band (10) extends over approximately half the length of the deflecting bridge (u/2) and that the two following arched sections with the radius (r2,r3) are located within the middle area of the respective side of the deflecting bridge (18) or within the end section of said side respectively. 4. The spinning frame according to any one of the preceding claims, wherein the diameter (D) of the roller pairs (wl,w2) in relation to the distance (s) of the rollers lay within the following value range: 5. The spinning frame according to any one of the preceding claims, wherein the end portion of the cradle (16) near the second roller pair (w2) is being arranged in such a way that it is being located between the end portion of the deflecting bridge (18) with the third arched section (r3) and the second roller pair (w2), so that an s-type course of the fibre band results between the roller pairs (wl ,w2). 6. The spinning frame according to any one of the preceding claims, wherein the deflecting bridge (14) and the cradle (16) are arranged in such a way that between the bottom apron (14) within the first arched section (rl) of the deflecting bridge (18) and the top apron (12) a gap is being formed which gradually becomes smaller in order to narrow the gap between the aprons (14,12), into which gap the fibre band (10) enters and where it is being clamped and that within the further arched sections (r2,r3) the clamping force onto the fibre band (10) increases. 7. A spinning trame with a dratting unit in which between a first roller pair (wl) and a second roller pair (w2) a deflecting bridge (18) with a bottom apron (14) as well as a cradle (16) with a top apron (12) are being arranged in such a way, in that a fibre band (10) being led between a roller pair (wl,w2) and the aprons (12,14) respectively, in the direction towards the clamping gap of the roller pair (w2), said fibre band is being guided on an s-shaped path, whereas the value of deflection on the s-shape path at least up to the turning point of the S preferably increases progressively. 8. A spinning frame with a drafting unit, in which between a first roller pair (wl) and a second roller pair (w2) a deflecting bridge (18) with a bottom apron (14) and a cradle (16) with a top apron (12) are being arranged, characterised in that a fibre band (10) running between the roller pairs (wl,w2) and the aprons (12,14) respectively, in the direction towards the clamping gap of the roller pair (w2) at least in the section of the deflecting bridge (18), is always being guided only on an arched track, whereat at least within a partial section of the deflecting bridge (18) near the second roller pair (w2) the deflection increases.

Documents:

235-mas-99 abstract-duplicate.pdf

235-mas-99 abstract.jpg

235-mas-99 abstract.pdf

235-mas-99 claims-duplicate.pdf

235-mas-99 claims.pdf

235-mas-99 correspondence-others.pdf

235-mas-99 correspondence-po.pdf

235-mas-99 description (complete)-duplicate.pdf

235-mas-99 description (complete).pdf

235-mas-99 drawings.pdf

235-mas-99 form-19.pdf

235-mas-99 form-2.pdf

235-mas-99 form-26.pdf

235-mas-99 form-4.pdf

235-mas-99 form-6.pdf

235-mas-99 others.pdf