Textiles: spinning – twisting – and twining – Apparatus and processes – With drafting
Reexamination Certificate
1999-10-04
2001-04-03
Calvert, John J. (Department: 3741)
Textiles: spinning, twisting, and twining
Apparatus and processes
With drafting
C019S035000, C019S228000, C028S252000, C057S261000, C057S296000, C057S328000, C057S333000, C226S007000, C226S097400, C226S196100
Reexamination Certificate
active
06209304
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a spinning device and, more particularly, to a spinning device with an inlet opening for a drafted sliver, a sliver guide and a hollow spindle for guiding the formed and drawn-off yarn, wherein means for generating an airflow are provided in the area of the sliver guide and the spindle, which acts on the fibers of the drafted sliver for twisting them.
BACKGROUND OF THE INVENTION
A device for producing a twisted yarn is known from German Patent Publication DE 40 36 119, wherein a guide member is arranged inside a nozzle block. A sliver traveling out of a drafting arrangement is drawn into the nozzle block and, near the inlet opening of a spindle, is subjected to an airflow rotating around the sliver for twisting it in this manner. A fiber strand guide takes the place of the inner fibers of the sliver as a so-called false core, because of which the fibers on the exterior circumferential surface of the fiber strand guide are forced to move along toward the inlet opening. In the course of this, the fibers are subjected to the action of the rotating airflow in an uncontrolled manner. Only the fiber strand guide arranged in the interior of the sliver counters an interfering false twist running out of the rotating area of the spindle in the direction toward the location where the sliver exits between the front rollers of the drafting arrangement. Subsequently the sliver is aspirated into the spindle by means of a suction airflow in order to create a yarn in this way.
Continuously increasing demands in regard to productivity and yarn properties are made on modern spinning machines.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to improve the device for sliver guidance in the type of spinning device described above in such a manner that an improved manufacturing process becomes possible.
In accordance with the invention, the sliver guide is comprised of fiber guide elements, which are spaced apart from each other and permit the free passage of a portion of the fibers constituting a core fiber bundle and the sliver guide is arranged outside of an imaginary center line of the traveling sliver such that at least a portion of the fibers is passed along the inward surface of the sliver guide. The spinning device can be designed such that the core fiber bundle is not deflected in the course of the passage of the sliver through the sliver guide. It is possible to achieve high production speeds with such an embodiment. Advantageously, the core fiber bundle includes at least 10%, preferably 20% to 40%, of the fibers. A good grasp and good guidance of the sliver between the fiber guide elements is achieved by means of the inner surface of the fiber guide elements, which is in contact with the sliver. In this manner, it is possible to divide the portions of the core and the sheath structures in a controlled manner into fibers which are oriented parallel in the longitudinal direction and into twisted fibers, wherein the core fibers only constitute a defined portion. The uncontrolled spreading away of fibers and fiber ends, as well as the continuation of the twisting in the direction toward the outlet of the sliver between the front rollers of the drafting arrangement is effectively prevented.
It is possible to improve the arrangement of the fibers which are oriented parallel in the longitudinal direction, and thereby the yarn properties, by means of yarn guide elements forming the core yarn bundle. An increase of the production speed is made possible at the same time.
In a further advantageous aspect of the invention, at least a portion of the fiber guide elements is embodied as a flat plate, by means of which it is possible to achieve a greater effect on the sliver. Alternatively, at least a portion of the fiber guide elements is preferably embodied to be needle-shaped. This permits the application of a particularly low pressure on the sliver. Fiber guide elements produced as flat plates or as needle-shaped can be easily manufactured. An embodiment of the fiber guide elements as parts of a single body, in which the fiber guide elements are made by cutting openings into a hollow cone, can also be simply and therefore cost-effectively produced and permits an improvement in the yarn values, particularly at high production speeds. The cutting of openings can be performed by erosion or drilling.
The embodiment can also be in the form of a compact sliver guide device with a sliver passage and fiber guide elements, wherein the sliver guide device is made of one piece. Simple handling and an easy and fast exchangeability are made possible because of the compact, one-piece design.
In a preferred embodiment, the fiber guide elements are arranged evenly distributed around the sliver, in particular concentrically or symmetrically, and the minimum distance of the fiber guide elements from the imaginary center line of the traveling sliver is slightly less than half the diameter of the sliver. Advantageously at least three fiber guide elements act on a single sliver. Such arrangements permit a specific metering or an increase of the guide and holding effects. The fiber guide elements preferably have the same shape in order to achieve as uniform an effect as possible distributed over the circumference of the sliver.
The inlet opening is preferably embodied as a slit-shaped sliver passage at least at the outlet side of the sliver, on whose oppositely located longitudinal sides the fiber guide elements are arranged, wherein the fiber guide elements extend at least approximately parallel in relation to the imaginary center line of the sliver, so that they cover a portion of the fiber flow from the sliver passage to approximately the vicinity of the inlet opening of the spindle and therefore remove it to the greatest possible extent from the effect of the rotating airflow. The retention of a core fiber bundle with primarily parallel and longitudinally oriented fibers in a largely undisturbed arrangement is made possible in this manner. By means of the spinning device in accordance with the invention, it is possible to achieve yarn speeds of 300 m/min and more, and therefore high productivity. Increased yarn strength and therefore an increased value of the finished yarn is also possible. A lower value can be selected for the pressure of the compressed air provided by the compressed air source. With the multitude of spinning stations in a modern spinning machine, a reduced air pressure leads to considerable cost reduction in the yarn production.
The fiber guide elements advantageously follow in the fiber flow direction immediately after the sliver passage and are arranged to be respectively centered on the longitudinal sides of the sliver passage, as viewed across the width of the sliver passage. The inside surfaces of the fiber guide elements facing the sliver extend in the direction of the fiber flow or in the direction of the respective free end of the fiber guide elements toward the center of the sliver, and the fiber guide elements have their smallest distance from each other at their free ends, by means of which the insertion of the sliver is made easier and the guidance of the passing sliver is improved.
The fiber guide elements are preferably designed resiliently such that, in case of an increase of the pressure exerted by the sliver on the inner surfaces of the fiber guide elements, they can be deflected transversely in relation to their extension. The free ends of the fiber guide elements oriented in the direction of movement preferably extend toward each other and have their smallest distance from each other at their free ends, but without touching each other. Advantageously, the fiber guide elements are designed such that their cross section increases toward the free ends. In this case, the core fiber bundle can extend centered on the imaginary axis of the device, and the imaginary center line of the sliver and the axis of the device can coincide. The insertion and the passage of the sliver is made easier by such an embo
Coll-Tortosa Liberto
Feuerlohn Helmut
Munill Frances Roig
Schulze Oliver
Tomero-Garcia Jose Antonio
Calvert John J.
Hurley Shaun R
Kennedy Covington Lobdell & Hickman L.L.P.
W. Schlafhorst AG & Co.
LandOfFree
Spinning device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Spinning device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Spinning device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2480518