Title of Invention

AN IMPROVED TRANSPORT BELT FOR TRANSPORTING A FIBRE STRAND TO BE PNEUMATICALLY CONDENSED

Abstract A transport belt for transporting a fibre strand to be pneumatically condensed comprises, at least in one area in which the fibre strand is guided, of an air-permeable woven material made of synthetic filaments. A percentage of these synthetic filaments is provided with an electroconductive surface, while a further percentage of the synthetic filaments is provided with a fat-repellent surface. The synthetic filaments having a fat-repellent surface and the synthetic filaments having an electroconductive surface can be arranged alternately. Equally possible is the arrangement of more synthetic filaments in the area in which the fibre strand is guided, while more synthetic filaments having an electroconductive surface are arranged adjacently to the fibre strand guiding area.
Full Text BACKGROUND AND SUMMARY OF THE INVENTION
Transport belt for transporting a fibre strand
The present invention relates to a transport belt for transporting a fibre strand to be
pneumatically condensed , said transport belt consisting at least in an area which
guides the fibre strand of an air-permeable woven material made of synthetic
filaments, and whereby a percentage of the synthetic filaments is provided with an
electroconductive surface.
When a drafted fibre strand is imparted a spinning twist directly downstream of the
front roller pair of the drafting unit, a so-called spinning triangle occurs at the nipping
line of the front roller pair. This comes about because the drafted fibre strand leaves
the drafting unit having a certain width and is twisted to a thread having a relatively
small diameter. The spinning triangle comprises lateral fibres, which are not properly
bound into the twisted thread and thus contribute little or nothing to the tensile
strength of the spun thread. In recent times, a condensing zone has been arranged
downstream of the drafting zone of the drafting unit, which condensing zone is in
turn bordered by a nipping line. Only downstream thereof is the thread imparted its
spinning twist. The fibres are bundled or condensed in the condensing zone,
whereby the fibre strand is so narrow when it leaves the nipping line furthest down-
stream that the feared spinning triangle is no longer noticeably disadvantageous. The
spun thread is then more even, tear-resistant and less hairy.
A wide range of arrangements for condensing a fibre strand are known. Many of
these function with an air-permeable transport belt, which transports the fibre strand
to be condensed slidingly over a suction slit. An arrangement of this type is
disclosed in German published patent application 199 11 333.
It should be mentioned here that in the terminology of this patent application the term
"pneumatic condensing" also includes those arrangements in which, apart from the
suction airstream, a further means, such as a transport component against a
slantingly positioned suction slit, also acts in and has an effect on the condensing
process.
A transport belt of the above type is prior art in German published patent application
10 2004 005 953. By means of the electroconductive surface of the synthetic
filaments, either the transport belt is prevented at the outset from being
electrostatically charged, or such electrostatic charges are reduced by means of
charge dissipation to a level harmless in practical application. The adherence of fibre
fly on the transport belt caused by electrostatic charges ceases to a great extent.
Contamination of such transport belts cannot, however, be completly prevented
hereby, as the fibre materials to be processed also contain to a certain degree
strongly adhering impurities, for example wool fat or honeydew. These strongly
adhering impurities are deposited over time on the transport belt and reduce the
condensing effect of the arrangement, as the air-permeability of the transport belt
lessens. As this a slow process, it is particularly dangerous as the decline in the
condensing effect is often only noticed at a late stage.
It is an object of the present invention to create an improved transport belt for the
pneumatic condensing process of a fibre strand which has a reduced tendency to
become contaminated.
This object has been achieved in accordance with the present invention in that a
percentage of the synthetic filaments has a fat-repellent surface.
This prevents the depositing of those strongly adhering impurities, which are not
influenced by a reduced electrostatic charge. The air-permeability of the woven
material is thus maintained for a significantly longer period of time.
Synthetic filaments with a fat-repelling surface can be produced in a variety of ways.
Particularly advantageous is a coating of the synthetic filaments with
polytetrafluoroethylene (also known under the brand name of Teflon) or with a
mixture of materials thereof. The synthetic filaments having an electrocondutive
surface are advantageously metallized synthetic filaments, where the synthetic
filaments are provided with a metal coating.
Advantageously the synthetic filaments having a fat-repelling surface and the
synthetic filaments having an electroconductive surface are alternately arranged.
Both properties are thus optimally combined. It can be provided, however, that more
synthetic filaments having a fat-repellent surface can be placed in the area guiding
the fibre strand. Thus that area in particular, in which the largest deposits of these
impurities occur, is protected against said impurities. The strongly adhering impurities
impurities are namely, in the main, released from the fibre strand to be condensed
and taken up by the transport belt.
In order to guarantee a sufficient electrostatic dissipation of the entire transport belt, it
can be advantageous to place the synthetic filaments having an electroconductive
surface in greater numbers adjacent to the area which guides the fibre strand.
The transport belt is particularly advantageous designed as a endless woven sieve
belt.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further objects, features and advantages of the present invention will
become more readily apparent from the following detailed description thereof when
taken in conjunction with the accompanying drawings wherein:
Figure 1 shows an arrangement for condensing a drafted, still twist-free fibre strand,
for which the transport belt of the present invention can be applied,
Figure 2 is a view in the direction of the arrow II of Figure 1, whereby the individual
rollers have been omitted for the purposes of greater clarity.
Of a spinning machine, in particular a ring spinning machine, only the area of an
arrangement 1 for condensing a drafted but still twist-free fibre strand 2 is shown in
Figures 1 and 2. The arrangement 1 is located directly downstream of a drafting unit
3, of which only the front roller pair 4, as well as an apron roller pair having a lower
apron 6 and a top apron 7 and being arranged upstream of the front roller pair 4, are
shown. The front roller pair 4 comprises a driven front bottom roller 8 as well as a
front pressure roller 9 flexibly pressed thereagainst. The front roller pair 4 defines a
front nipping line 10, which forms the end of the drafting zone of the drafting unit 3.
In the drafting unit 3, a sliver or a roving 11 is drafted in transport direction A to the
desired degree of fineness in the known way. The drafting process ends at the front
nipping line 10 and from this point on the drafted but still twist-free fibre fibre strand 2
is formed. In order to reduce the known and disadvantageous spinning triangle, the
fibre strand 2 is condensed directly downstream of the front nipping line 10 in a
condensing zone 12. The arrangement 1 provided for the condensing comprises an
air-permeable transport belt 13, which transports the fibre strand 2 to be condensed
through the condensing zone 12. The arrangement 1 comprises further a suction
channel 14, which is designed as a hollow profile in which a vacuum prevails, and
which can extend over a plurality of spinning positions. The suction channel 14 is
designed on its side facing the condensing zone 12 as a sliding surface 15 for
guiding the transport belt 13.
In the sliding surface 15 a suction slit 16 is located, which is arranged slightly
diagonally to the direction of motion of the transport belt 13, so that one lateral edge
of the suction slit 16 is designed as a fibre guiding edge 17 in relation to the fibre
strand 2 to be condensed. The fibre strand 2 travels along this fibre guiding edge 17
during the condensing process, whereby the fibres in the fibre strand 17 are bundled
or condensed transversely to the direction of motion of the transport belt 13, during
which the fibre strand 2 is rolled in somewhat. The suction channel 14 is connected
via a vacuum conduit 18, which is located at a distance from the suction slit 16, to a
vacuum source (not shown). Insofar as the suction channel 14 extends over a
plurality of spinning positions, only one vacuum conduit 18 needs to be present per
suction channel 14.
The condensing zone 12 is bordered on its exit side by a nipping roller 19, which
presses the fibre strand 2 and the transport belt 13 onto the sliding surface 15 and
thereby defines a delivery nipping line 20, which functions as a twist block with
regard to the spinning twist to be applied. The nipping roller 19 drives the transport
belt 13 and is in turn driven by the front pressure roller 9 via a transfer wheel 21, for
example, in the form of a toothed wheel.
Downstream of the delivery nipping line 20 the forming thread 22 receives its
spinning twist, in that it is fed in delivery direction B to a twist device (not shown), for
example a ring spindle. The delivery nipping line 20 functions as a twist block in
regard to the spinning twist, so that the spinning twist does not extend back into the
condensing zone 12.
On the side of the suction channel 14 facing away from the suction slit 16, the
transport belt 13 is tensioned by means of a tensioning element 23, which can be
designed as a stationary rod or also as a guiding roller. The tensioning element 23 is
hereby so arranged that the transport belt 13 lies with a light pressure on the front
bottom roller 8. As the transport belt 13 and the front bottom roller 8 travel in opposite
directions to one another at the point of contact, the transport belt 13 is cleaned of
any adhering fibre fly.
As can be seen in Figure 2, the initial area 24 of the suction slit 16 comprises an
extension which permits the fibre strand 2, traversing slightly in transverse direction
to be reliably taken hold of by the suction slit 16. The traverse motion serves in
particular to ensure that the front pressure roller 9 has a longer life.
As already mentioned, the transport belt 13 consists, in its area which guides the
fibre strand 2, of a woven material 25. A number of the synthetic filaments 26 are
provided with an electroconductive surface in order to prevent the woven material 25
from becoming electrostatically charged and thus becoming clogged with fibre fly.
The fibre material forming the fibre strand 2 can, depending on the mix, contain
strongly adhering impurities such as wool fat or honey dew. These can be deposited
in the woven material 25 in the area which guides the fibre strand 2. This cannot be
prevented solely by synthetic fibres 26 having an electroconductive surface. It is
therefore provided according to the present invention that a further number of
synthetic filaments 27 have a fat-repellent surface. Clogging of the perforations
naturally occuring in the woven material 25 by strongly adhering impurities is thus
greatly reduced.
In the embodiment shown in Figure 2, the synthetic fibres having an electro-
conductive surface 26 are arranged transversely to the direction of transport A of the
fibre strand 2. Those synthetic filaments having a fat-repelling surface 27 are
arranged parallel to the transport direction A and interlace in the woven material with
the synthetic filaments 26 having an electroconductive surface. In an embodiment of
the present invention it can, however, be provided that the synthetic filaments 27
having a fat-repelling surface and the synthetic filaments 26 having an
electroconductive surface can be arranged alternately adjacent to one another, for
example parallel to the direction of transport A. It is also advantageous to arrange
numbers of identical synthetic filaments adjacently in groups. For example, in the
area which guides the fibres strand 2, synthetic filaments 27 having a fat-repelling
surface can be used in increased numbers. The largest amount of strongly adhering
impurities occur in this particular area above the suction slit 16, and it is therefore
advantageous when the fat-repelling surface is fortified by increased numbers of fat-
repelling filaments. In order to ensure the electroconductivity of the transport belt 13,
it can be advantageous to place the synthetic filaments 26 having an
electroconductive surface in greater numbers adjacent to the area guiding the fib/e
strand.
CLAIMS:
1. A transport belt (13) for transporting a fibre strand (2) to be pneumatically
condensed, said transport belt consisting at least in an area which guides the
fibre strand (2) of an air-permeable woven material (25) made of synthetic
filaments (26, 27), and whereby a percentage of the synthetic filaments (26)
is provided with an electroconductive surface, characterized in that a further
percentage of the synthetic filaments (27) have a fat-repelling surface.
2. A transport belt according to claim 1, characterized in that the synthetic
filaments (27) having a fat-repelling surface are arranged in increased
numbers in the area which guides the fibre strand (2).
3. A transport belt according to claim 1 or 2, characterized in that the synthetic
filaments (26) having an electroconductive surface are arranged in increased
numbers adjacent to the area which guides the fibre strand (2).
4. A transport belt according to any of the claims 1 to 3, characterized in that
the synthetic filaments (27) having a fat-repelling surface and the synthetic
filaments (26) having an electroconductive surface are arranged alternately.
5. A transport belt according to any of the claims 1 to 4, characterized in that the
synthetic filaments (26) having an electroconductive surface are designed as
metallized synthetic filaments.

A transport belt for transporting a fibre strand to be pneumatically condensed comprises, at least in one area in which the fibre strand is guided, of an air-permeable woven material made of synthetic filaments. A percentage of these
synthetic filaments is provided with an electroconductive surface, while a further
percentage of the synthetic filaments is provided with a fat-repellent surface. The
synthetic filaments having a fat-repellent surface and the synthetic filaments having an electroconductive surface can be arranged alternately. Equally possible is the
arrangement of more synthetic filaments in the area in which the fibre strand is guided, while more synthetic filaments having an electroconductive surface are arranged adjacently to the fibre strand guiding area.

Documents:

170-KOL-2006-ABSTRACT.1.1.pdf

170-kol-2006-abstract.pdf

170-KOL-2006-AMENDED CLAIMS.pdf

170-KOL-2006-ASSIGNMENT.1.3.pdf

170-KOL-2006-ASSIGNMENT.pdf

170-kol-2006-claims.pdf

170-KOL-2006-CORRESPONDENCE-1.1.pdf

170-KOL-2006-CORRESPONDENCE-1.2.pdf

170-KOL-2006-CORRESPONDENCE.1.3.pdf

170-kol-2006-correspondence.pdf

170-KOL-2006-DESCRIPTION (COMPLETE).1.1.pdf

170-kol-2006-description (complete).pdf

170-KOL-2006-DRAWINGS.1.1.pdf

170-kol-2006-drawings.pdf

170-KOL-2006-EXAMINATION REPORT REPLY RECIEVED.pdf

170-KOL-2006-EXAMINATION REPORT.1.3.pdf

170-KOL-2006-EXAMINATION REPORT.pdf

170-KOL-2006-FORM 1.1.1.pdf

170-kol-2006-form 1.pdf

170-KOL-2006-FORM 18.1.3.pdf

170-kol-2006-form 18.pdf

170-KOL-2006-FORM 2.1.1.pdf

170-kol-2006-form 2.pdf

170-KOL-2006-FORM 26.1.3.pdf

170-kol-2006-form 26.pdf

170-KOL-2006-FORM 3-1.1.pdf

170-KOL-2006-FORM 3.1.3.pdf

170-kol-2006-form 3.pdf

170-KOL-2006-FORM 5.1.3.pdf

170-kol-2006-form 5.pdf

170-KOL-2006-GRANTED-ABSTRACT.pdf

170-KOL-2006-GRANTED-CLAIMS.pdf

170-KOL-2006-GRANTED-DESCRIPTION (COMPLETE).pdf

170-KOL-2006-GRANTED-DRAWINGS.pdf

170-KOL-2006-GRANTED-FORM 1.pdf

170-KOL-2006-GRANTED-FORM 2.pdf

170-KOL-2006-GRANTED-LETTER PATENT.pdf

170-KOL-2006-GRANTED-SPECIFICATION.pdf

170-KOL-2006-OTHERS DOCUMENTS.pdf

170-KOL-2006-OTHERS.1.3.pdf

170-KOL-2006-OTHERS.pdf

170-KOL-2006-PETITION UNDER RULE 137.pdf

170-kol-2006-priority document.pdf

170-KOL-2006-REPLY TO EXAMINATION REPORT.1.3.pdf

170-KOL-2006-REPLY TO EXAMINATION REPORT.pdf

170-kol-2006-specification.pdf

170-kol-2006-translated copy of priority document.pdf


Patent Number 247839
Indian Patent Application Number 170/KOL/2006
PG Journal Number 21/2011
Publication Date 27-May-2011
Grant Date 25-May-2011
Date of Filing 24-Feb-2006
Name of Patentee MASCHINENFABRIK RIETER AG
Applicant Address KLOSTERSTRASSE 20, 8406 WINTERTHUR
Inventors:
# Inventor's Name Inventor's Address
1 NORBERT BRUNK TALSTRASSE 5/1, D-73337, BAD UBERKINGEN
PCT International Classification Number N/A
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 102005016441.2 2005-04-04 Germany