Title of Invention

SPINNING FRAME WITH A COMPACTING DEVICE FOR A FIBRE BAND

Abstract

In a spinning frame with a compacting device a compacting element (V) with a guiding surface (VF) is being provided with holes (VB). The roughness of the guiding surface in circumferential direction of the compacting elemet (V) is being increased by providing grooves (VN) which are basically being arranged parallel or inclined to the axis (A) of the compacting element (V). By increasing the roughness the guiding surface (VF) can generate higher drawing forces onto a fibre band (F) in its running direction (L), in particular if the compacting element (V) operates together with a pressure roller.

Full Text

The present invention relates to a spinning frame with a compacting device for a fibre band consisting of a compacting element with a moving guiding surface, which is being provided with holes and with a suction device which is being connected to the inside of the compacting element. From the US patent US-4488397 a device of the state of the art is known whereat a fibre band is being guided over a moving guiding surface of a compacting element, whereat the guiding surface generates a drawing force onto the fibre band and whereat an air stream being applied onto the side of the fibre band by suction air being directed towards the inside of the guiding surface, thereby pressing laterally projecting fibres onto said the fibre band. Furthermore, such a compacting element prevents the unwinding of a twist in the fibre band, the yam respectively in downstream direction of the compacting element, if the compacting element is followed by a twisting device. Such a compacting device is preferably arranged in the spinning frame between a drafting unit and a ring spinning device, whereat the compacting element can be an outlet roller of the drafting unit, which operates together with a pressure roller. In case of the above mentioned US patent the compacting element is being arranged after the drafting unit. Experience has shown that the drawing force being generated by the compacting element on the fibre band is not sufficient under all conditions, in order to guide the fibre band sufficiently. It is therefore the object of the present invention to improve a compacting device in this sense. Accordingly the present invention provides a spinning frame with a compacting device for a fibre band consisting of a compacting element with a moving guiding surface, which is being provided with holes and with a suction device, which is being connected to the inside of the compacting element so that air can flow through the holes along the guiding surface and to the inside of the compacting device, characterised in that the roughness of the moving guiding surface in relation to conventional compacting elements in moving direction of the guiding surface is increased while the roughness of the guiding surface at right angle to the moving direction is not being increased. The basic aim of the invention is to increase the roughness of the moving guiding surface in running direction of the fibre band, while the roughness in cross direction remains low. Thus a better fibre guidance is achieved without thereby reducing the sidewise shiftability of the fibres. The increase of the roughness in running direction of the fibre band is preferably achieved by a channelure, that is by grooves within the guiding surface in cross direction to the running direction of the fibre band. With a drum-type compacting element the channelure can for instance be parallel or be inclined to its axis. An arrow-shaped channel structure can also be taken into consideration. By increasing the roughness, through the channel structure respectively, a better guidance of the fibres is being obtained, in particular in the case if the compacting element operates together with a pressure roller being pressed against it, whereat a considerably increased clamping effect of the fibres between the compacting element and the roller results. The improved clamping and guidance respectively is effective for all relevant yarn parameters in a distinct positive sense. The spinning frame is being equipped with a compacting device for a fibre band, comprising a compacting element of a moving guiding surface, which is being provided with holes, and with a suction device being connected to the inner space of the compacting element, so that through the holes the air can flow along the guiding surfaces and enter the inner space of compacting element, whereat the roughness of the moving guiding surface in relation to conventional compacting elements in the moving direction of the guiding surface is being increased considerably, while the roughness of the guiding surface in cross direction to the moving surface is not being increased. The moving guiding surface is being provided with protrusions or grooves which are oriented at a right angle or slantedly to the moving direction of the guiding surface. The guiding surface is being provided with a greater number of holes in the running direction of the fibre band, the moving direction of the guiding surface respectively. In cross direction to the running direction of the fibre band, the moving direction of the guiding surface respectively, preferably a number of holes or rows of holes can be arranged next to each other. Seen in the running direction of the fibre band, the moving direction of the guiding surface respectively, preferably every other hole is being located within the base of a groove. The holes are preferably of circular shape with a diameter of between 0.7 and 1.1 mm, some of which are being positioned in grooves of a width of between 0.8 and 1.2 mm and a depth of between 0.3 and 0.8 mm. For a good result in compacting it is important that some of the holes are being positioned in protrusions and others in grooves. The compacting element is preferably provided as an outlet roller in a drafting unit, which is followed by a twisting device. The flanks of the protrusions, the side walls of the recesses respectively, are to be made as steep as possible, that is at an angle of maximum 10° in relation to the normal onto the surface of the compacting element over which the fibre band is being led. This assures that the surface that guides the fibres on its circumference of the compacting element is being interrupted as evenly as possible, thus resulting in a drawing operation of the fibre band without disturbance. In the following the invention is being described in more detail according to an exemplified embodiment wherein show: figure 1 a compacting element in a meridian cross section figure 2 a detail of a cross sectional view at a right angle to the axis of the compacting element, and figure 3 a top view of the guiding surface of the compacting element at an enlarged scale. figure 4 a side view of a protrusion VO as a detail from figure 2 with the inclination angle of a flank of a protrusion in relation to the radius line from the centre of the compacting element. The compacting element V according to figure 1 is made as a drum. Over the outer surface of said drum a fibre band f is being led in circumferential direction of the compacting element V. The compacting element V has two running tracks for fibre bands, whereat two moving guiding surface VF with penetrations or holes VB are being arranged next to each other. The fibre band or the fibre bands F respectively is (are) in contact with the compacting element V over an enclosing angle of at least 90°. Through the holes VB according to figure 3 air is being suctioned into the inner space of the compacting element V, thereby pressing laterally projecting fibres RF against the fibre band F and whereat during the following twisting process said laterally projecting fibres are being better integrated into the fibre band. The holes VB have a diameter D of between 0.7 and 1.2 mm and are being arranged next to each other at an axial spacing of between 1.0 and 1.5 mm, and whereas the rows of holes in circumferential direction L are being arranged offset towards each other. The grooves VN or protrusions VO run at a right angle to the running direction L of the fibre band F whereas every other row of said holes VB running more or less in the direction of the axis A is being located within the base of a groove. The grooves have a width b of between 0.8 and 1.2 mm and have rounded corners at their base. The rounding u according to figure 2 is preferably 0.2 mm and the depth t of the groove is less than 1 mm. The moving guiding surface VF describes a radius r of between 50 and 90 mm. Figure 1 shows that the moving guiding surface VF of the compacting element V is being located on a hub N by which the compacting element V is being fastened onto a shaft or onto a drawing roller. The protrusions VO and grooves VN at the circumference of the compacting element V run at right angle or at a defined angle to the moving direction L of the guiding surface VF. The structure of the guiding surface VF with the protrusions VO and the grooves VN can be called channelure, whereas the profile of the channelure can be shaped by roll-forming or preferable drawing operation. In particular the flanks of the protrusions VO according to figure 4 are to be formed as steep as possible. Figure 4 shows an inclination of the flanks of a protrusion VO In relation to a radius line of the compacting element with the angle a, whereat said inclination includes an angle of 8° at maximum, preferably less than 3° and in particular 0°. A steep angle assures that the width b of the grooves VN, the extension of the protrusions VO respectively, in moving direction L of the guiding surface VF remain as constant as possible whereby an even draft of the fibre band F is made possible. In effect the elevations and recesses in the guiding surface VF are to be formed in such a way that the flank inclination of the protrusions at least nearly is oriented at a right angle or almost at a right angle in relation to the moving direction of the guiding surface VF. WE CLAIM I. Spinning frame with a compacting device for a fibre band (F) consisting of a compacting element (V) with a moving guiding surface (VF), which is being provided with holes (VB) and with a suction device, which is being connected to the inside of the compacting element (V) so that air flows through the holes (VB) along the guiding surface (VF) and to the inside of the compacting device (V), characterised in that the roughness of the moving guiding surface (VF) in relation to conventional compacting elements in moving direction (L) of the guiding surface (VF) is increased while the roughness of the guiding surface (VF) at right angle to the moving direction (L) is not being increased. 2. Spinning frame as claimed in claim 1, wherein the moving guiding surface (VF) is being provided with protrusions (VO) or grooves (VN) which are directed at right angle or at a defined angle to the moving direction (L) of the guiding surface (VF). 3. Spinning frame as claimed in any one of the claims 1 or 2, wherein the guiding surface (VF) is being provided with a greater number of holes (VB) in the running direction (L) of the fibre band (F), the moving direction (L) of the guiding surface (VF) respectively. 4. Spinning frame as claimed in any one of the claims 1 to 3, wherein in cross direction to the running direction (L) of the fibre band (F), the moving direction (L) of the guiding surface (VF) respectively several holes (VB) are being arranged next to each other. 5. Spinning frame as claimed in any one of the claims 1 to 4, wherein seen in the running direction (L) of the fibre band (F), the moving direction (L) of the guiding surface (VF) respectively, every other hole (VB) is being located within the base of a groove (VN) and within a protrusion (VO). 6. Spinning frame as claimed in any one of the claims 1 to 5, wherein the holes (VB) are of circular shape with a diameter D of between 0.7 and 1.3 mm and whereof some are being positioned within grooves (VN) of a width of between 0.8 and 1.2 mm and a depth of between 0.3 and 0.8 mm and others are being positioned in protrusions (VO). 7. Spinning frame as claimed in any one of the claims 1 to 6, wherein the roughness of the guiding surface (VF) is structured in such a way that the flank inclinations of the protrusions in the guiding surface (VF) are nearly vertical or vertical in relation to the moving direction (L) of the guiding surface (VF). 8. Spinning frame as claimed in claim 7, the inclination of a flank of a protrusion (VO) in relation to a radius line from the centre of the compacting element (V) is at maximum 8°, less than 3° and in particular 0°. 9. Spinning frame with a compacting device for a fibre band, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

0487-mas-1999 abstract-duplicate.pdf

0487-mas-1999 abstract.jpg

0487-mas-1999 abstract.pdf

0487-mas-1999 claims-duplicate.pdf

0487-mas-1999 claims.pdf

0487-mas-1999 correspondence-others.pdf

0487-mas-1999 correspondence-po.pdf

0487-mas-1999 description (complete)-duplicate.pdf

0487-mas-1999 description (complete).pdf

0487-mas-1999 drawings-duplicate.pdf

0487-mas-1999 drawings.pdf

0487-mas-1999 form-19.pdf

0487-mas-1999 form-2.pdf

0487-mas-1999 form-26.pdf

0487-mas-1999 form-4.pdf

0487-mas-1999 form-6.pdf

0487-mas-1999 others.pdf