Arrangement for spinning staple fibers into a yarn

An arrangement is disclosed for spinning staple fibers to a yarn which has a feeding and opening device which opens up fiber material supplied in the form of slivers into a individual fibers, and a disk-type collecting element which takes over the separated fibers. It is provided that the collecting element has a conical fiber collecting surface which ascends toward the outside with centrifugal forces assisting in compacting the separated fibers to a composite.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention relates to an arrangement for spinning staple fibers into a 
yarn of the type having a feeding and opening device which opens up fiber 
material supplied in the form of a sliver into individual fibers. A 
disk-shaped collecting element takes over the separated yarns and has a 
rotating, air permeable collecting surface which is aligned approximately 
tangentially with respect to an opening roller of the feeding and opening 
device. A suction device is assigned to the collecting surface on the side 
facing away from the opening roller and facing the collecting surface by 
means of a suction slot which tapers in the circumferential direction to a 
withdrawal point which is followed by a twisting element and a withdrawal 
device. 
In an arrangement of the initially mentioned type (German Patent Document 
DE-A 36 24 190), the drafting of the fed fiber material to the desired 
yarn size takes place with the opening-up into individual fibers. The 
separated fibers are then guided to the collecting surface already in an 
amount which corresponds to the yarn size to be spun so that a subsequent 
doubling is no longer required. The separated fibers are bundled to form a 
fiber composite only transversely to the direction of their continued 
transport. In the case of the known construction, a flat, plane disk (FIG. 
25) is arranged as the collecting element from which the fiber composite 
is withdrawn against the rotating direction of the disk while a twist is 
introduced. In this construction, the fibers are held exclusively by the 
effect of the suction device against the centrifugal force which exists 
because of the rotation of the disk. In another embodiment, the fibers are 
fed from the outside onto a conical rotation body which is provided with a 
suction device on the inside. In this embodiment, the fibers are also held 
against the centrifugal forces only by the suction effect. In another 
embodiment (FIG. 27), the fibers are fed to the interior surface of a 
cylindrical collecting element. In this construction, the interior surface 
supports the fibers against the centrifugal force. In this case, the 
collecting of the fibers takes place exclusively by means of the effect of 
the suction slot tapering in the transport direction. 
It is also known (French Patent Document FR-A 23 60 695) to feed the 
separated fibers, by way of a fiber feeding duct, following an opening 
roller of a feeding and opening device, into a rotor which has a wall 
which ascends toward the outside in a truncated-cone-shaped manner. As a 
result of the centrifugal force, the fibers are to ascend over the edge of 
the rotor after which they are collected in a stationary collecting groove 
from which they are withdrawn through a rotating element. 
It is also known (European Patent Document EP-B 0 236 324) to feed the 
fibers separated by a feeding and opening device to a moving collecting 
surface on which they are doubled so that the desired yarn size is 
obtained. The collecting surface will then advance the fiber composite to 
a withdrawal point at which, while being rotated at the same time, the 
fiber composite is withdrawn into the direction in which it is fed. In 
this case, the withdrawal speed corresponds essentially to the speed at 
which the fiber composite is fed by the collecting surface. 
It is an object of the invention to provide an arrangement of the initially 
mentioned type in which the centrifugal forces participate in the 
compacting of the separated fibers to a fiber composite while, however, 
the holding of the fibers against the centrifugal forces does not have to 
be carried out exclusively by the effect of the suction device. 
This object is achieved according to preferred embodiments of the present 
invention in that the disk-shaped collecting element is provided with a 
conical area which ascends toward the outside and is constructed as a 
fiber collecting surface. 
In this construction, the centrifugal forces participate in the compacting 
of the separated fibers to a fiber composite while, however, at the same 
time, the fiber collecting surface supports the fibers at least partially 
against the centrifugal forces so that a lower air throughput is required 
for the suction device. 
In a further development of the invention, it is provided that the 
collecting element is constructed in the shape of a bowl, the edge area of 
which serves as the fiber collecting surface. In a further development of 
the invention, it is provided that the bowl has a vertical axis of 
rotation and the fiber collecting surface ascends toward the outside and 
upward. This has the advantage that the gravitational force affecting the 
fibers partially counteracts the centrifugal forces so that a further 
reduction of the power consumption is possible with respect to the suction 
device. 
In a further development of the invention, it is provided that the fiber 
collecting surface is bounded toward the outside by means of a collecting 
groove. This collecting groove is used on the one hand as a safety measure 
to prevent fiber losses by a throwing-off of fibers from the collecting 
surface while, on the other hand, it improves the collecting operation. It 
is preferable and expedient for the suction slot to end in front of the 
withdrawal point. As a result, it is ensured that all fibers are collected 
in the collecting groove. 
In a further development of the invention, it is provided that a roller is 
arranged at the withdrawal point of the fiber collecting groove which is 
situated opposite the fiber collecting surface. The withdrawal point can 
be exactly defined by means of this roller. 
In a further development of the invention, it is provided that the roller 
is loaded by means of an elastic contact pressure device in the direction 
of the collecting surface. 
The roller presses against the collecting surface with a relatively slight 
force in the order of 10N. This has the result that the twist introduced 
by the twisting element is a false twist so that a yarn is created which 
in principle corresponds to a yarn manufactured by pneumatic false-twist 
spinning. However, in contrast to the known pneumatic false-twist spinning 
which operates with drafting units, because of the feeding and opening 
device, an arrangement is achieved that has a much higher capacity. When 
the contact pressure is adjusted to be even lower or when the roller is 
left out completely, the twisting element introduces a true twist into the 
fiber composite so that then a true-twisted yarn is created. 
In a further development of the invention, it is provided that the 
withdrawal direction of the withdrawal device is essentially tangential to 
the fiber collecting surface in the area of the withdrawal point and has a 
moving component which continues the moving component of the fiber 
collecting surface at the withdrawal point. As a result, it is avoided 
that a significant deflection of the fiber composite occurs in this area 
which may cause a tangling of the fibers. 
In a further development of the invention, it is provided that a driven 
suction roller is arranged between the withdrawal device and the 
withdrawal point, the suction area of which is directed at the travelling 
yarn and the circumferential speed of which in the travelling direction of 
the yarn is higher than the withdrawal speed of the withdrawal device. 
This suction roller takes along, at an increased speed, edge fibers which 
project or spread away from the fiber composite, that is, at a speed which 
is higher than the speed of the core of the fiber composite. These 
spread-away edge fibers which are taken along at an increased speed will 
then, at the time of the opening-up of the false twist, form wind-around 
fibers behind the twisting element which provide strength to the spun yarn 
and which are wound around the yarn core in a very uniform manner. 
Other objects, advantages and novel features of the present invention will 
become apparent from the following detailed description of the invention 
when considered in conjunction with the accompanying drawings.

DETAILED DESCRIPTION OF THE DRAWINGS 
The arrangement illustrated in FIG. 1 is a component of a spinning machine 
which, at least on one side of the machine, is provided with a plurality 
of arrangements of this type which are arranged in a row. The arrangement 
comprises a feeding and opening device by means of which four slivers 1, 
2, 3, 4, which approach in the direction of the arrow (A) from a feed 
which is not shown, are fed simultaneously and are opened up into 
individual fibers which subsequently are spun to a yarn 5 which travels in 
the direction of the arrow (B) to a wind-up device, which is not shown, 
and is wound onto a spool package there. 
The feeding and opening device comprises a driven feeding roller 6 which, 
in a manner not shown in detail, interacts with a feeding table and which 
guides the four slivers 1, 2, 3, 4 simultaneously to an opening roller 7 
which is driven at a much higher speed. On its circumference, the opening 
roller 7 is provided with a mounting of teeth or needles which combs out 
the slivers 1 to 4 and in the process separates them into individual 
fibers. By means of a shaft 9, the opening roller 7 is disposed in a 
bearing housing 10. The shaft 9 is provided with a driving wharve 11 
against which a tangential belt 12 moves along which moves through the 
machine in the longitudinal direction of the machine and simultaneously 
drives the opening rollers 7 of all arrangements of one side of the 
machine. 
The opening roller 7 which, in a manner not shown in detail, is surrounded 
by a housing having a delivery opening, transfers the separated fibers to 
a collecting surface 13 which is arranged approximately tangentially with 
respect to the circumference of the opening roller 7. The collecting 
surface 13 is a component of a bowl-shaped or plate-shaped collecting 
element 14. The collecting element 14, which is open toward the top, by 
means of a vertical shaft 29, is disposed in a bearing housing 30 which is 
arranged in a machine frame. On the shaft 29, a driving wharve 31 is 
arranged which is driven by means of a tangential belt 32 moving through 
in the longitudinal direction of the machine. The rotational speed of the 
collecting element 14 is designed such that the collecting surface 13, at 
the point of its smallest radius facing the opening roller, still has a 
circumferential speed which corresponds at least to the circumferential 
speed of the opening roller 7. The collecting element 14 rotates in the 
direction of the arrow (C) (FIG. 2) in such a manner that the moving 
direction of the arriving separated yarns remains the same. 
The collecting element 14 has a flat plane bottom 15 which is followed by 
an edge area 16 which is constructed in the shape of a truncated cone and 
expands in the upward and outward direction. This edge area 16 contains 
the fiber collecting surface 13. The edge area 16 is provided with a 
perforation 17. On the underside 18 of the edge area 16, which is opposite 
the opening roller 7, a stationary suction device 19 is arranged which 
contains an approximately half-ring-shaped vacuum chamber 20 which, in a 
manner not shown in detail, is connected to a vacuum source. By way of a 
suction slot 21, the vacuum chamber 20 is open toward the underside 18 of 
the edge area 16 by which the course of the fiber collecting surface 13 is 
formed As shown particularly in FIG. 2, the collecting surface 13 has, in 
the area in which it takes over the fibers from the opening roller 7, a 
width (x) in the radial direction which corresponds approximately to the 
working width (z) of the opening roller 7. In the circumferential 
direction (C) of the collecting element 14, the fiber collecting surface 
13 tapers to a final width (y) which determines a withdrawal point 49. The 
outer edge 22 of the suction slot 21 describes a circular arc which is 
coaxial to the collecting element 14. The inner edge 23 extends in a 
spiral shape toward the outside from the receiving point to the withdrawal 
point 49. In this area, the suction slot 21 and therefore also the fiber 
collecting surface 13 still only have a narrow width (y) which is in the 
range of a few millimeters, that is, in the order of 5 mm and less. 
The fibers arriving from the opening roller 7 are taken over as individual 
fibers 24 in the starting area of the suction slot 21 and are then 
compacted or bundled to a fiber composite 25 on their way to the 
withdrawal point 49. In this case, there will no longer be any doubling, 
that is, the individual fibers 24 are supplied to the collecting element 
14 already in an amount which corresponds to the number of fibers in the 
cross-section of the spun yarn 5. A doubling takes place with the feed of 
several slivers (1 to 4), that is, before the opening up into individual 
fibers 24. 
The movements of fibers 24 on the fiber collecting surface 13 are 
illustrated by means of FIG. 3. The separated fibers 24 coming from the 
opening roller 7 are fed to the fiber collecting surface 13 largely 
uniformly distributed over the whole initial width (x). The fibers 33, 34, 
35 deposited on the outer circumferential area remain essentially in the 
position in which they were deposited. As a result of the friction force 
generated between them and the fiber collecting surface 13 because of the 
suction effect, they are held against the centrifugal force. The fibers 
36, 37, 38 arriving in the inner edge area of the fiber collecting surface 
13 are first also deposited on the collecting surface 13, which is 
subjected to suction, and are held in this position. However, as soon as 
they reach and move beyond the edge 23 of the suction slot 21, the 
friction force with respect to the fiber collecting surface 13 is reduced 
so that, as a result of the then predominating centrifugal force, they are 
moved toward the outside, in which case they largely roll off and retain 
their straight-line position. Since, in this case, they move into areas of 
a higher circumferential speed, they are additionally stretched. Thus, at 
the withdrawal point 49, that is, at the end of the fiber collecting 
surface 13, a fiber composite or a fiber bundle is created which 
essentially has the width (y). 
At the withdrawal point 49, the fiber composite is withdrawn by means of a 
withdrawal device 27. The withdrawal speed of the withdrawal device 27 
corresponds at least approximately to the circumferential speed of the 
fiber collecting surface 13 at the withdrawal point 49. In the top view 
according to FIG. 2, the withdrawal direction (B) extends approximately 
tangentially to the fiber collecting surface 13 in the area of the 
withdrawal point 49 and with one moving component in this direction. In 
order to be able to withdraw the yarn 5 from the plate-shaped collecting 
element 14, the withdrawal also takes place diagonally in the upward 
direction. 
The withdrawal of the fiber composite 25 at the withdrawal point 49 takes 
place while introducing a twist into the fiber composite. For this 
purpose, a twisting element 26, preferably a pneumatic twisting element, 
which in a known manner consists of one or two pneumatic twisting nozzles, 
is arranged between the withdrawal point 49 and the withdrawal device 27. 
In order to be able to precisely define the withdrawal point 49, as shown 
in FIG. 1, a roller 28 is arranged in this area which is pressed by means 
of a preferably adjustable contact pressure force controller 28, against 
the truncated-cone-shaped edge area 16 of the collecting element 14 at the 
withdrawal point 49. The roller 28 provides that the twist introduced by 
the twisting element 26 does not run back into the fiber composite 25 by 
way of the withdrawal point 49. Thus, a yarn 5 is created which, with 
respect to its characteristics, corresponds to a false-twisted yarn, that 
is, a yarn with an essentially untwisted yarn core and fiber ends wound 
around it on the outside. If, on the other hand, the contact pressure 
force of the roller 28 is reduced or the roller 28 is left out completely, 
the provided twist can move back into the fiber composite 25 so that a 
true-twisted yarn 5 is created. It is therefore possible to spin by means 
of the arrangement a false-twisted yarn or a true-twisted yarn or a 
mixture of both. 
The embodiment according to FIG. 4, in its basic principle, corresponds to 
the embodiment according to FIGS. 1 to 3. However, in the embodiment 
according to FIG. 4, an opening roller 39 is provided which has a 
truncated-cone-shaped shell surface. Also in this embodiment, the 
generating line of this opening roller 39 extends in parallel to the edge 
area 16 of the collecting element 14. In the case of this type of an 
opening roller 39, as early as during the combing-out of the slivers (1 to 
4), the effect will occur that the separated fibers travel to the area of 
the larger diameter of the opening roller 39 so that a certain collecting 
or bundling effect occurs already before the fibers reach the collecting 
surface 13. It is therefore possible to design the initial width (x) of 
the fiber collecting surface 13, that is, the width of the suction slot 
21, slightly smaller. 
The embodiment according to FIG. 5, in its basic construction, corresponds 
to the embodiment according to FIGS. 1 to 3. As an addition, in the 
embodiment according to FIG. 5, a suction roller 40 is arranged between 
the twisting element 26 and the withdrawal point 49, the axis of the 
suction roller extending transversely to the travelling direction of the 
yarn 5. The suction roller 40, which is provided with a perforation 41, 
comprises a suction insert 42 which is provided with a suction slot 43 
which is situated opposite (facing) the area around which the withdrawn 
yarn 5 winds. The suction roller 40 is driven to a speed which is 
approximately by one half higher than the withdrawal speed of the 
withdrawal device 27. The suction roller 40, which rotates in the 
travelling direction of the yarn (direction of the arrow D), spreads edge 
fibers 50 away from the fiber composite which subsequently are taken along 
by the suction roller 40 at an increased speed while the core of the fiber 
composite or yarn slides over the suction roller 40 at the withdrawal 
speed. As a result, it is achieved that the edge fibers 50, during the 
providing of the false twist, are wound around the yarn core with a 
specified direction so that also subsequently, after the opening-up of the 
false twist, the edge fibers are wound around the yarn core in a defined 
manner behind the twisting element 26. 
In the embodiment according the FIG. 6, which in principle corresponds to 
the embodiment according to FIGS. 1 to 3, it is additionally provided that 
the bowl-shaped or plate-shaped collecting element 44, at the outer end of 
the truncated-cone-shaped edge area 16, is provided with a fiber 
collecting groove 45. This fiber collecting groove 45 is housed in an edge 
which follows the truncated-cone-shaped edge area 16 in the axial 
direction. This fiber collecting groove 45 has the purpose of avoiding the 
loss of fibers and, in addition, permitting an additional compacting of 
the fiber composite. In this case, it may be provided that the suction 
slot 21 ends in the area of the fiber collecting groove 45 or in front of 
the withdrawal point so that then all fibers will subsequently arrive in 
the fiber collecting groove 45. 
In the embodiment according to FIG. 6, it is also provided that the 
withdrawal point is defined by a disk-shaped roller 46, the outer contour 
of which is designed such that it matches the inner contour of the fiber 
collecting groove 45. The roller 46, which with its shaft 47 is disposed 
in a bearing housing 48, is driven by friction. By means of the contact 
pressure force of the roller 46, which is preferably adjustable, the type 
of the spun yarn 5 is determined. When the roller 46 prevents a 
running-back of the twist provided by means of the twisting element 26 
into the yarn composite, a truly false-spun yarn is obtained. When, on the 
other hand, the contact pressure force of the roller 46 is so slight (or 
the roller 46 is completely absent), the provided twist runs back into the 
fiber composite so that a yarn with a true twist is created. By means of 
the selection of the contact pressure force, mixed forms can also be 
produced, that is, a mixed yarn form between a real false-twisted yarn and 
a completely true-twisted yarn. 
The arrangement according to the invention results in a number of 
advantages. Because of the use of a feeding and opening device of an 
opening roller, high spinning speeds may be reached, that is, 
significantly higher speeds than by means of drafting units which cause 
problems at high speeds. Since the fiber material is fed by means of 
several individual slivers 1 to 4, a good doubling effect is achieved as 
early as during the feed. By means of the adjustment of loading forces in 
the area of the withdrawal point, the character of the yarn may be 
influenced. By means of the shape of the connecting surface of the 
collecting element, a fiber loss may be reduced while at the same time the 
power consumption is also decreased. 
Although the invention has been described and illustrated in detail, it is 
to be clearly understood that the same is by way of illustration and 
example, and is not to be taken by way of limitation. The spirit and scope 
of the present invention are to be limited only by the terms of the 
appended claims.