Textiles: fiber preparation – Working – Carding
Reexamination Certificate
2002-03-14
2003-05-20
Welch, Gary L (Department: 3765)
Textiles: fiber preparation
Working
Carding
C019S105000, C019S205000
Reexamination Certificate
active
06564430
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to an apparatus for processing textile fibers, comprising a processing element having a first working surface substantially in the form of a regular cylinder surface and rotatable preferably around the axis of the cylinder, like a take-in roller of a card., and at least one carding element having a further working surface facing the first working surface, a carding element suitable for assembling such an apparatus, and support elements adapted to be used for assembling these carding elements and sawtooth wire strips.
2. Description of the Related Art
Apparatuses of the above-described type are used, for example, in the form of initial loosening sections in cards or carding combs suitable for producing a fiber fleece with uniformily aligned fibers from a fiber material with nonuniformily aligned fibers. The working of such cards or carding combs is explained below with reference to
FIGS. 3
to
5
.
FIG. 3
shows schematically the basic structure of a card or carding comb. Accordingly, the card comprises a feeder channel generally denoted by
12
for introducing the fiber material of nonaligned fibers into an initial loosening section
20
. The fiber material is transferred with this initial loosening section
20
to the cylinder
30
of the card. This cylinder is a roller which on its outer surface is provieded with a steel hook or sawtooth filleting set. During operation, the cylinder is rotated around its axis. The fibers supplied from the initial loosening section are picked up by the filleting set and aligned in the direction of rotation of the roller. In order to improve the fiber alignment, there are used rods
32
distributed circumferentially over the outer surface of the cylinder. These rods have a working surface facing the outer surface of the cylinder in the position of operation, with the working surface likewise configured as a hook and/or sawtooth filleting set made of steel. The rods can be stationary or adapted to be moved in a direction opposite to the direction of cylinder rotation. Finally, the fiber fleece is removed with a doffing cylinder
40
and transported to further processing. In the card described with reference to
FIG. 3
, the initial loosening section serves, on the one hand, for controlled feeding of the disorderd fiber material to the cylinder and, on the other hand, for uniformly distributing the fiber material over the entire axial length of the cylinder.
FIG. 4
shows in detail this initial loosening section
20
. In the loosening section
20
shown in the figure, there are provided a total of three initial take-in rollers
22
,
24
, and
26
rotatable around the roller axes
22
a
,
24
a
, and
26
a
in the directions indicated by the arrows A. Each of the take-in rollers
22
,
24
, and
26
has a working surface in the form of the outer surface of a regular cylinder, which may be provided with a steel hook or sawtooth filleting set. Particularly in the case of high-output cards and high-output carding combs for processing short-staple and long-staple textile fibers of natural or synthetic polymers, it is common practice to associate so-called stationary carding elements
23
,
25
, and
27
with the various take-in rollers
22
,
24
, and
26
in order to improve the fiber distribution. The arrangement of these stationary carding elements is shown in
FIG. 5
as an example for the stationary carding element
27
.
FIG. 5
a
is a section along a plane vertical to the axis
26
a
of the roller and
FIG. 5
b
is a top view of the stationary carding element
27
. It can be seen in
FIG. 5
a
that the stationary carding element
27
is formed basically by a support element
27
a
and sawtooth wire sections
27
b
affixed to this support element
27
a
. These sawtooth wire sections
27
b
extend approximately tangentially to the outer surface of the take-in roller
26
which is likewise provided with a steel sawtooth set. As shown in
FIG. 5
b
, the stationary carding element has a plurality of sawtooth wire sections arranged in side-by-side relationship and attached to the support element
27
a
. In conventional cards, the stationary carding elements have a width of about 32 to 52 mm and are made from cast iron, steel, aluminium, magnesium or synthetic materials; between the tips of the sawtooth wire strips
27
b
and those of the set of take-in rollers there is maintained a minimum spacing of the order of 0.1 to 1.0 mm. In the region of the greatest approach of the sawtooth wire strips
27
b
to the filleting set of the take-in roller
26
, there takes place levelling of the fibers, and this causes a first alignment of the fiber material and uniform distribution of this fiber material. The width of the zone along which levelling of the fibers takes place corresponds approximately to the average fiber length of the fiber material introduced.
When the cards shown in
FIGS. 3
to
5
were used, it was observed that nonuniform fiber distribution may occur in the fiber fleece taken from the doffing cylinder
40
, particularly at high processing rates.
SUMMARY OF THE INVENTION
In view of these problems of the state of the art, the problem underlying the invention is to provide an apparatus of the above-described type with which even at high processing rates uniform fiber distribution can be obtained in the fiber fleece taken from the card or carding comb and to design a carding element suitable for assembling such an apparatus and to provide suitable support elements and sawtooth wire strips for such a carding element.
According to the invention, this problem is solved by further development of the known apparatus, characterised basically in that the form of the further working surface of the carding element approximates the form of the processing element's, like the taker-in's, first working surface having basically the form of the outer surface of a regular cylinder on a plane vertically intersecting the axis of the cylinder.
The invention resides on the finding that the nonuniform distribution of the fibers in the fiber fleece taken with the doffing roller from the cylinder results already from the fiber processing in the region of the initial loosening section, because, as a consequence of the tangential approach of the working surface of the stationary carding element to the corresponding roller sets, there is available only a very narrow zone in which effective fiber levelling occurs so that the resulting distribution of the fibers is not adequate in each instance. In the inventive development of the known apparatus, the zone in which effective fiber levelling can take place is enlarged by approximating the form of the working surface of the carding element to the cylinders' working surface in the form of the outer surface of a regular cylinder so that an overall improved fiber distribution is obtained. It turned out that the air turbulence, which is caused by approximating the form of the working surface of the carding elements to the form of the outer surface of a regular cylinder, is acceptable in the zone of the effective fiber levelling in view of the improved enlargement of this zone.
In principle, the approximation of the working surface of the carding elements to the form of the outer surface of a regular cylinder can be obtained by any concave shape of this working surface. In particular, there can be considered an arched form of the carding element's working surface coaxial with the first working surface in order to provide a particularly wide zone in which effective fiber levelling can take place. With a view to obtaining the lowest possible air turbulence in the region of the fiber levelling zone while enlarging the same at the same time, it proved to be particularly convenient to approximate the working surface of the carding elements to the first working surface in the form of the outer surface of a regular cylinder by a polygonal progression having polygon sections approximately tangential to the first working surface on the plan
Graf + Cie AG
Welch Gary L
LandOfFree
Apparatus for processing textile fibers does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for processing textile fibers, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for processing textile fibers will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3005725