Textiles: knitting – Independent-needle machines – Circular
Reexamination Certificate
2000-05-31
2001-06-19
Worrell, Danny (Department: 3741)
Textiles: knitting
Independent-needle machines
Circular
C066S168000
Reexamination Certificate
active
06247335
ABSTRACT:
The present disclosure relates to the subject matter disclosed in German Application No. 199 25 171.1 of Jun. 1, 1999, the entire specification of which is incorporated herein by reference.
The invention relates to a circular knitting machine for producing knitted fabrics with combed-in fibers, comprising a needle cylinder, at least one carding device with a comb-in wheel and an extraction device for waste fibers.
A circular knitting machine of this type is known from EP 0 742 852 B1.
Such circular knitting machines are used to work clusters of fiber bands (sliver clusters) into knit loops.
Proceeding from this state of the art the object underlying the invention is to provide a circular knitting machine which produces knitted fabrics of a high quality and requires as little maintenance as possible.
This object is accomplished in accordance with the invention, in the circular knitting machine specified at the outset, in that the extraction device has at least one extraction nozzle for generating a directional extraction flow.
By providing an extraction nozzle, the extraction flow may be directed and, in particular, those areas of the circular knitting machine, in which more waster fibers are generated, may be acted upon with the extraction flow. Such an area is, in particular, the comb-in area, in which a needle hook of a knitting needle removes a cluster of fibers from the comb-in wheel. The mechanical action of this needle hook on the fibers can lead to the detachment of fiber particles. Since detached fiber particles, on the one hand, settle in the circular knitting machine and soil it and, on the other hand, fall onto the knitted fabric and may reduce the quality of the knit, the extraction device is provided for extraction. In the device of EP 0 742 852 B1, the extraction device is of a funnel-shaped design with one end open downwards so that no selective direction of the extraction flow is possible but only a type of “global” suction effect occurs. With this device known from the state of the art waste fibers cannot, therefore, be carried away to an adequate and also precise extent. This problem is solved by the inventive extraction nozzles.
The inventive extraction device may be used particularly advantageously when the circular knitting machine comprises an air flow guiding device for orienting fibers in an orientation air flow. The air flow guiding device also serves to work the free ends of the fiber clusters into the stitch or loop fabric. As a result, a fiber-band, high-pile knitted fabric with reversed fiber cluster loops can, in particular, be produced.
As a result of the orientation air flow, bundles of fibers are oriented for working into a knitted fabric at their free ends. Two types of fluid flows are therefore effective in such a circular knitting machine, namely the extraction flow and an orientation air flow. In the device known from EP 0 742 852 B1 the orientation air flow is affected by the extraction flow since the latter is non-directional and acts globally on a knitting area. In the case of the inventive device, on the other hand, the extraction flow may be directed and then only those areas, in which waste fibers occur, are selectively acted upon locally.
It is, therefore, particularly favorable when the extraction nozzle or extraction nozzles are arranged and designed in such a manner that the respective extraction flow is essentially decoupled from the orientation air flow. As a result, the orientation air flow remains unaffected by the extraction flow and the quality of the take-up of the clusters of fibers is increased in comparison with the device known from the state of the art.
It is favorable to have an extraction nozzle associated with each carding device. As a result, waster fibers are taken away from their main source and a uniform take-up results for each carding device. It is particularly advantageous when an extraction nozzle is associated with each comb-in wheel since the waste fibers result, in particular, at the comb-in wheel.
In order to act on a comb-in wheel selectively with an extraction flow, a longitudinal axis of the extraction nozzle associated with the comb-in wheel is, advantageously, essentially at right angles to an axis of rotation of the comb-in wheel so that no cross flows occur.
Furthermore, it is particularly advantageous when the longitudinal axis of the extraction nozzle is located in a plane of symmetry of the comb-in wheel essentially at right angles to the axis of rotation of the comb-in wheel. This results in an optimum alignment of extraction nozzle and comb-in wheel.
In order to improve the extraction of fiber particles even more, the extraction flow is favorably directed in the same direction as the rotation of the comb-in wheel. As a result, waste fibers loosened from a needle hook are extracted directly and cannot settle at inaccessible locations. Again, waste fibers which are only partially detached and which could become completely loosened during further rotation of the comb-in wheel and then settle in inaccessible areas of the circular knitting machine are, in certain circumstances, loosened entirely by the assisting effect of the extraction flow so that they cannot settle in the machine.
It is particularly favorable when an extraction nozzle is arranged and designed such that the effective area of the extraction flow covers a comb-in area of the comb-in wheel in order to act selectively on one of the main sources of waste fibers with the extraction flow.
An extraction nozzle is favorably arranged and designed such that a lower area of the comb-in wheel facing the needle cylinder is acted upon by the extraction flow. On the one hand, this makes a complete detachment of partially loosened waster fibers possible; on the other hand, the extraction flow is still directed as a result since the area which has to be acted upon is not too large.
In order to extract waste fibers as completely as possible from the comb-in area, the width of a nozzle opening is advantageously greater than the width of the associated comb-in wheel. The width of a nozzle opening is favorably somewhat greater than the width of an associated comb-in wheel, for example, in the order of magnitude of 5 to 10%. The extraction flow is still directed and covers the comb-in area well.
A nozzle opening of an extraction nozzle is favorably arranged at an angle to a horizontal plane. As a result, the extraction flow is directed at an angle upwards and, in particular, may be formed essentially tangential to the comb-in wheel. This makes a good discharge of waste particles possible.
It is favorable when an extraction nozzle comprises an aperture element and a connecting element, wherein the aperture element has the same cross-sectional area as the connecting element. As a result, the aperture may, on the one hand, be adapted such that a desired area is acted upon by the extraction flow; on the other hand, the suction capacity is not reduced as a result. The cross section of the aperture element is favorably broadened in a horizontal direction in comparison with the connecting element since in this way, in particular, the comb-in area can be well acted upon by an extraction flow.
In a particularly favorable variation of one embodiment the inventive circular knitting machine has a plurality of carding devices, wherein each carding device comprises its own air flow means for orienting the fibers to be combed in. In this way, large areas of knitted fabric may be produced in an effective manner.
So far, no comments have been given concerning the design of the air flow means. An air flow means favorably has at least one suction element and at least one blower element. Free ends of clusters of fibers may be drawn in by the suction element so that the cluster of fibers can be grasped by a needle hook. This effect can likewise be achieved by a blower element which orients the free ends of the cluster of fibers by means of its blast air flow; the two flows can also interact to increase the effect.
The air flow means favorably comprises a take-up air flow
Kunde Klaus
Mueller Armin
Schaeberle Erwin
Lipsitz Barry R.
Terrot Strickmaschinen GmbH
Worrell Danny
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