The present application claims priority from German Patent Application No. 10 2005 012 251.5, dated 15 Mar. 2005, the entire disclosure of which is incorporated herein by reference.
The invention relates to an apparatus on a carding machine for processing textile fibres, for example cotton, synthetic fibres and the like, with a cylinder. Generally, in such an apparatus, in the preliminary carding zone, after carding zone and/or underneath carding zone, covering elements lie opposite the cylinder clothing, and a fixed carding element is associated with at least one cover element, the spacing of the cylinder clothing with respect to the clothing of the fixed carding element (carding nip) being smaller than the spacing with respect to the cover element.
In practice, covering elements are located only a small distance apart from the clothed outer surface of the high-speed cylinder. In addition to cover plates without clothing there are also routinely present clothed fixed carding elements having at least one clothing strip. In many cases, relatively short non-clothed cover profiles extend tangentially to the cylinder clothing.
In a known apparatus (EP 0 687 754 A) a cylinder casing segment is provided which serves as support for three fixed carding bars. Upstream of the first (seen in the direction of rotation of the cylinder) fixed carding bar (clothing strip), the cylinder casing segment has a non-clothed extension piece which covers the cylinder. The surface of the extension piece is flat and extends parallel to the cylinder clothing. Furthermore, the spacing between the extension piece and the cylinder clothing in the circumferential direction of the cylinder is throughout larger than the spacing between the clothing of the fixed carding element and the cylinder clothing. In particular, the spacing of the end of the extension piece associated with the fixed carding element with respect to the clothing of the fixed carding element is substantial, and there is a step. As a result, air turbulence occurs upstream of the fixed carding element, which in an undesirable manner results in increased nep formation in the fibre material. A further problem is that the turbulence leads to an increased pressure difference at the fixed carding elements, to increased heating of the components involved, to higher fibre loading and to clogging of the clothing strips of the fixed carding elements.
It is an aim of the invention to provide an apparatus of the kind described at the beginning that avoids or mitigates the mentioned disadvantages, that especially reduces nep formation, allows improved carding work and gives a better carding result.
The invention provides a carding apparatus comprising:
a carding cylinder;
a fixed carding element having a clothed surface opposed, at a first spacing, to the cylinder;
a cover element opposed to the cylinder at a second spacing greater than said first spacing; and
an air guide element arranged between said cover element and said carding element and so positioned that the spacing of the air guide element from the cylinder in the region of the cover element is greater than the spacing of the air guide element in the region of the fixed carding element.
By allowing gradual reduction of the spacing between the air guide element and the cylinder clothing to a spacing that is the same as or smaller than the spacing between the cylinder clothing and the clothing of the fixed carding element, or the at least one clothing strip, troublesome air turbulence upstream or downstream of the fixed carding element can be avoided. The air entrained by the cylinder can flow smoothly into or out of the carding nip between the cylinder and the fixed carding element. According to the invention, a flow guide element is mounted upstream and/or downstream of the fixed carding element so that fibres and air are continuously supplied to the narrow carding nip or are conveyed away from the carding nip, that is to say the space upstream of the carding element becomes successively narrower or wider. In respect of the cylinder clothing, the narrowest cover profile spacing is brought nearer to the tip spacing of the fixed carding element. In particular, the first tips of the clothing strip of the fixed carding element are, in terms of flow, covered or overlapped by the air guide element. Because the turbulence upstream or downstream of a fixed carding element is minimised or avoided, the following advantages inter alia are achieved: more uniform carding with a higher level of nep reduction, that is to say better quality; less heat generated by the machine as a whole; pressure differences at the cylinder reduced; loading on the first tips of a carding element minimised, because those tips are covered in terms of flow; more uniform distribution of the fibres, that is to say more homogeneous carding over the length of the carding elements; and less wear to clothings on the fixed carding elements. A considerable improvement both in the carding operation and the carding result (fibre web, sliver) is thereby achieved.
There may be an air guide element arranged upstream of the fixed carding element, the spacing—seen in the direction of rotation of the cylinder—gradually decreasing. As well or instead there may be an air guide element arranged downstream of the fixed carding element, the spacing—seen in the direction of rotation of the cylinder—gradually increasing. Advantageously, the spacing of the end of an upstream air guide element that is associated with the fixed carding element is the same as or smaller than the spacing between the clothing of the fixed carding element and the cylinder clothing. Advantageously, the spacing of the end of a downstream air guide element is the same as or smaller than the spacing between the clothing of the fixed carding element and the cylinder clothing. The cover element may be a cover profile, for example an extruded profile. Advantageously, in respect of the cylinder clothing the spacing of the end of the cover element that is associated with the air guide element and the spacing of the end of the air guide element that is associated with the cover element are substantially the same, and may be, for example, about 40/1000″. Advantageously, the spacing between the cylinder clothing and the clothing of the fixed carding element is about from 13/1000″ to 15/1000″. Advantageously, the spacing of the air guide element with respect to the cylinder clothing is adjustable. In one preferred arrangement, the end of the air guide element that faces the cover element is mounted on a pivot bearing. Advantageously, the spacing of the end of the air guide element that faces the fixed carding element with respect to the cylinder clothing is adjustable. Advantageously, the angle between the air guide element and a tangent on the cylinder clothing is adjustable, and is preferably adjustable in the range of about from 0.2° to 7°.
Advantageously, the fixed carding element has at least one clothing strip. Advantageously, the clothing of the at least one clothing strip is flat. Instead, the clothings of the clothing strip may be arranged at an angle to one another.
In one arrangement according to the invention, the air guide element is a separate component. In another arrangement of the invention, the air guide element is integrated into the frame of the fixed carding element. For example, the air guide element may be arranged upstream and/or downstream in the frame of a clothing strip. Advantageously, the air guide element is arranged adjacently in the frame of a clothing strip. Advantageously, the air guide element is part of the frame and is arranged upstream and/or downstream of the at least one clothing strip. The air guide element may instead be mounted outside on the frame.
The air guide element may consist of a flat plate or the like. The air guide may instead have a curved shape which faces the cylinder clothing. Advantageously, there is a clothing on the surface of the air guide element that faces the cylinder clothing. It is preferred that the size of the angle of the guide element relative to the cylinder be such that it does not cause separation of the air flow.
In an advantageous embodiment, a pivot joint for the air guide element is connected to a drive device, for example, a motor. Advantageously, the drive device is connected to an electronic control and regulation device Advantageously, the air guide element is automatically adjustable. Advantageously, the spacing of the air guide element with respect to the cylinder clothing is automatically adjustable.
In accordance with the invention, a carding apparatus as defined including an air guide element may be arranged in one or more of the preliminary carding zone, and the region between the licker-in and the rear card top guide roller. Where present, the drive device for the air guide element may be manually operable. Where present, a pivot joint for the air guide element may be mounted on the cover element. The air guide element may be a part of the cover element. The air guide element may be formed integrally on the cover element.
The invention also provides an apparatus on a carding machine for processing textile fibres, for example cotton, synthetic fibres or the like, with a cylinder, wherein, in the preliminary carding zone, after carding zone and/or underneath carding zone, covering elements lie opposite the cylinder clothing and wherein a fixed carding element is associated with at least one cover element, the spacing of the cylinder clothing with respect to the clothing of the fixed carding element (carding nip) being smaller than the spacing with respect to the cover element, in which between at least one clothing strip of the fixed carding element and a cover element arranged upstream and/or downstream of the fixed carding element—seen in the direction of rotation of the cylinder—there is arranged an air guide element the spacing of which with respect to the cylinder clothing gradually decreases or increases.
a shows the carding elements according to
a shows the spacing of the boundary region between the cover profile and the air guide element with respect to the cylinder clothing;
b shows the boundary region between the cover profile and a clothing strip and the spacings between the cylinder clothing and the cover profile and the clothing strip;
With reference to
Referring to
In the embodiment of
The plane of the tips of the clothing strip 20a′ can be flat, the narrowest spacing a with respect to the curved cylinder clothing 4a being, for example, 0.25 mm. In that case, the spacing of the first tips with respect to the cylinder clothing 4a is greater than 0.25 mm. The first tips are inevitably overlapped when the end of the air guide element 25 is set at a spacing of 0.25 mm with respect to the cylinder clothing 4a.
In the embodiment of
In the arrangement of
The pivot joints 26a, 26a can be mounted on a stationary holding element, frame or the like (not shown). In another development, the pivot joints 26a, 26b can be mounted in fixed position on the cover profiles 24a, 24b, respectively.
In the embodiment of
In a further embodiment shown in
In the embodiment of
In the embodiment of
Upstream of a fixed carding element, which is usually positioned tangentially with respect to the cylinder 4, a flow guide element 25 is so mounted that fibres and air are supplied continuously to the narrow carding nip a, that is to say the space upstream of the carding element 20 becomes successively narrower. Because the turbulence upstream of a fixed carding element is minimised, the following advantages are obtained:
On the licker-in side (see
When fixed carding elements 20 are used, two points are important:
If gentle carding is preferred, the stream of fibres should not strike the first tips but should rather make contact with the clothing strip after those tips.
In the known apparatus, turbulence occurring upstream of a clothing strip can be identified by the fact that there are no deposits in the form of trash and dust between the first tips of a clothing strip, but instead such deposits are not found, even on the base of the clothing, until 7 mm after the first tips. As a result of the turbulence upstream of the fixed carding element, the flow even by-passes the first tips. The apparatus 17′, 17″ according to the invention avoids such turbulence.
According to the invention, the narrowest guide profile spacing is advantageously brought closer to the tip spacing of the fixed carding element, more advantageously with the air guide element even being in the same position as or overlapping the first tips of the fixed carding element. Overlapping automatically occurs when a fixed carding element is set to a spacing of 0.25 mm with respect to the cylinder and the guide element is likewise set to that spacing of 0.25 mm. Because the fixed carding element is usually mounted tangentially with respect to the cylinder, the curvature of the cylinder results in there being a larger spacing between the tips of the fixed carding element and the cylinder at the beginning and end of the fixed carding element and accordingly results in significant overlapping.
Although the foregoing invention has been described in detail by way of illustration and example for purposes of understanding, it will be obvious that changes and modifications may be practised within the scope of the appended claims.
Number | Date | Country | Kind |
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10 2005 012 251.5 | Mar 2005 | DE | national |