Fiber feed passage arrangement for friction spinning devices

In a friction spinning device comprising a fiber opening assembly, a fiber feed passage arrangement, and friction spinning drums cooperating with the fiber feed passage arrangement, the fiber feed passage arrangement is divided in its longitudal direction into two passage or channel halves. At the separation or parting joints or gaps formed by connection flanges associated with the passage halves, there can be provided recesses so that a respective connecting slot is formed between the cross-section of the fiber feed passage arrangement and the separation or parting joints. In this way, there can be substantially avoided contact of fibers with the separation or parting joints.

BACKGROUND OF THE INVENTION 
The present invention relates to a new and improved fiber feed passage or 
channel arrangement for friction spinning devices for pneumatic feed of 
textile fibers between a fiber opening assembly and a spinning unit, the 
fiber feed passage arrangement being formed by an assembly of at least two 
adjoining or neighboring interconnected parts or components. 
From European Patent Application No. 98,380 (corresponding to U.S. Pat. No. 
4,441,310, granted Apr. 10, 1984), a fiber feed passage arrangement of the 
aforementioned general type is already known to the art. This fiber feed 
passage arrangement comprises a straight sidewall and an adjoining 
L-shaped sidewall. The straight sidewall has a flat surface against which 
bears the foot portion of the cooperating L-shaped counter-wall so that a 
separating joint or gap, even if a fine one, is formed. 
Such separating joints or gaps have the disadvantage that, even when they 
are very fine, they still tend to form proturberances or shoulders which 
retain the very fine fibers transported through the fiber feed passage 
arrangement. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind, it is a primary object of the 
present invention to provide a new and improved construction of a fiber 
feed passage arrangement for friction spinning devices which does not 
exhibit the aforementioned drawbacks and limitations of the prior art 
constructions. 
Another important object of the present invention aims at providing a new 
and improved construction of a fiber feed passage arrangement for friction 
spinning devices in which there is effectively precluded or extensively 
reduced, the possibility of undesirably entrapping or retaining fibers in 
the internal fiber feed passage or channel of the fiber feed passage 
arrangement. 
Yet a further important object of the present invention is directed to the 
provision of a new and improved construction of a fiber feed passage or 
channel arrangement for friction spinning devices, wherein the fiber feed 
passage or channel arrangement is structured such that there is 
effectively precluded or largely minimized the danger of undesirably 
entrapping fibers within the fiber feed passage or channel arrangement 
while the latter is nonetheless relatively simple and economical in its 
design. 
Now in order to implement these and still further objects of the invention, 
which will become more readily apparent as the description proceeds, the 
present invention is manifested by the features that the fine separation 
or parting joints, also referred to as joint crevices, which are formed 
during assembly of the longitudinal parts or components, are shifted out 
of the region of the actual cross-section of the fiber feed passage or 
channel arrangement such that between each separation or parting joint and 
the passage or channel cross-section of the fiber feed passage arrangement 
there is provided a slot or gap connecting each associated separation or 
parting joint with the cross-section of the fiber feed passage 
arrangement. 
Some of the more notable advantages realized by the present invention 
reside in the fact that, on the one hand, there are practically no 
manufacturing or production limitations for the type of fiber feed passage 
or channel arrangement and, on the other hand, in spite of the multi-part 
or divided fiber feed passage arrangement there is essentially no danger 
that fibers will be caught or entrapped at the separation or parting 
joints.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Describing now the drawings, it is to be understood that only enough of the 
exemplary embodiments of friction spinning devices and their related 
structure have been shown to enable those skilled in the art to readily 
understand the underlying principles and concepts of the present invention 
while simplifying the illustration of the drawings. Turning attention now 
specifically to FIGS. 1 and 2, there is shown therein a friction spinning 
device 1 comprising a fiber opening assembly 2 known from open-end rotor 
spinning techniques, a fiber feed passage or channel arrangement 3 
adjoining the fiber opening assembly 2, and a first friction spinning drum 
4, only partly illustrated. The second friction spinning drum, which 
cooperates with the first friction spinning drum 4, has not been shown for 
simplicity of illustration. 
By means of these two coacting friction spinning drums, the fibers 
delivered by the fiber feed passage or channel arrangement 3 are twisted 
together to form a yarn which is then withdrawn by any suitable withdrawal 
means not here specifically illustrated and such yarn is then wound-up. In 
accordance with the previously mentioned definition, the two friction 
spinning drums form, for example, a spinning unit. 
Such friction spinning devices are well known in this art and are 
illustrated and described, for example, in U.S. Pat. No. 4,130,983, 
granted Dec. 26, 1978 to which reference may be readily had. 
The fiber opening assembly 2 comprises a housing 5, a rotatably and 
drivably supported opening roller 6, a feed roller 8 feeding a fiber 
sliver 7, and a so-called troughplate 9 receiving the fiber sliver 7. 
The bearings and the drive of the friction spinning drums, the opening 
roller 6 and the feed roller 8 are known and are also not subject matter 
of the present invention, and therefore are not here further described in 
any detail. 
The fiber feed passage or channel arrangement 3 comprises a first passage 
or channel half 10, a second passage or channel half 11 and a connecting 
or connector flange 12. The two passage or channel passage halves 10 and 
11 define or delimit an internal fiber feed channel or passage 45 and 
constitute longitudinal or longitudinally extending passage or channel 
halves. In other words, the fiber feed passage arrangement 3 is divided 
into these two passage or channel passage halves 10 and 11 in its 
longitudinal direction and is held together by connecting flanges 13 and 
14, for example with the aid of screws or bolts or by means of soldered 
joints. The connecting or connector flange 12 serves to secure the fiber 
feed passage or channel arrangement 3 to the housing 5 of the fiber 
opening assembly 2. 
If the two passage halves 10 and 11 of the fiber feed passage arrangement 3 
are held together by means of screws or bolts or other releasable 
connections, then it is advantageous to divide the connecting or connector 
flange 12 also into two halves which are each then associated with 
respective related ones of the passage or channel halves 10 and 11. 
The mutually contacting separating or joint surfaces of the connecting or 
connector flanges 13 and 14 must be constructed such that the separation 
or parting joints 17 and 18, respectively, (indicated in FIG. 1), formed 
due to the mutual contact of the connecting or connector flanges 13 and 
14, have practically no locations at which fibers could be entrapped or 
caught. 
FIGS. 3 and 4 show, as a variant to the fiber feed passage or channel 
arrangement 3 of FIG. 1, a further construction of a fiber feed passage or 
channel arrangement 3.1. FIGS. 5 and 6 show, on an enlarged scale, details 
of the arrangement of FIG. 4 and indicated in such FIG. 4 by the encircled 
regions designated with reference characters A and B, respectively. 
The difference between the fiber feed passage or channel arrangement 3.1 of 
the embodiment of FIGS. 3 and 4 and the fiber feed passage or channel 
arrangement 3 of the embodiment of FIG. 1 is that, in each of the 
connecting or joining flanges 13.1 and 14.1 (FIGS. 5 and 6, respectively) 
there is provided a respective recess 15' and 16' which forms a slot 15 
and 16, respectively. Each such slot 15 and 16 possesses the slot depth L 
and slot breadth or width W. 
By means of each of these slots 15 and 16, the fine separation or parting 
joints 17 and 18, respectively, which are formed due to the assembly of 
the connecting flanges 13.1 and 14.1, are shifted out of the region of the 
passage or channel cross-section i.e., out of the region of the internal 
fiber feed channel or passage 45 to the base of the associated slots 15 
and 16, respectively. The separation or parting joints 17 and 18 are 
located in the middle of the base of each associated slot 15 and 16, 
respectively. 
The advantage of these slots 15 and 16, respectively, is that, with an 
advantageous relationship between the slot depth L and the slot width W, 
with a minimum slot width of 0.1 mm and a maximum slot width of 0.5 mm, 
the fibers conveyed or fed in the passage or channel cross-section or 
internal passage 45 of the fiber feed passage or channel arrangement 3.1 
are subjected to less risk of coming into contact with the separation or 
parting joints 17 and 18, respectively, so that there is a smaller danger 
that these fibers will be entrapped or caught in such separation or 
parting joints 17 and 18. 
The minimum relationship of slot depth L to slot width W is 5:1 and for 
practical reasons the maximum relationship L:W is 10:1. 
Each slot or gap 15 and 16 is formed or extends throughout the complete 
length of the fiber feed passage or channel arrangement 3.1, with the 
exception of the connecting flange 12, and can have a widened or enlarged 
portion at the region of the outlet end or discharge region of the feed 
passage or channel arrangement 3.1. 
FIGS. 7 and 8 show a variant embodiment as compared with the embodiment 
illustrated in FIGS. 4, 5 and 6. Here, the separation or parting joints 17 
and 18 are not located in the middle of the base of the associated slot 15 
and 16, respectively, but are located completely in one corner of the base 
of each such associated slot 15 and 16. This variant is produced in that 
each recess 15' and 16' forming the associated slot 15 and 16, 
respectively, is provided in only one of the two connecting flanges 13.1 
or 14.1, for example, in the embodiment under discussion, in the 
connecting flange 13.1 as clearly shown in FIGS. 7 and 8. Since in all 
other respects the same elements or parts are present in this embodiment 
as in the embodiment of FIGS. 5 and 6, these elements or parts of the 
embodiment of FIGS. 7 and 8 are conveniently generally indicated with the 
same reference numerals. 
The advantages of this variant embodiment resides in the simpler 
manufacture of a precise separating or parting joint or gap in which there 
is no possibility of shifting the joint surfaces relative to each other in 
such a manner that the base of the slot, stated in an exaggerated fashion, 
takes on a step-shaped configuration. 
FIGS. 9 and 10 show a respective substantially boot-shaped slot or gap 15.1 
and 16.1. Each foot portion 19 and 20 of the slots or gaps 15.1 and 16.1, 
respectively, is directed upwardly in the showing of FIGS. 9 and 10. It is 
not, however, essential to the invention whether each such foot portion 19 
and 20 is directed upwardly, downwardly or at an angle which differs from 
a right angle, as such right angle has been shown in FIGS. 9 and 10. An 
essential point is simply that the separation or parting joints 17 and 18 
are not located in the region of the leg portions 21 and 22, respectively, 
but are laterally shifted and to a certain degree are hidden at the end of 
the foot portions 19 and 20, respectively. 
With the exception of the adaptations caused by the substantially 
boot-shaped slots or gaps 15.1 and 16.1, the elements or parts or 
components of FIGS. 9 and 10 are essentially the same as those of FIGS. 7 
and 8, and therefore the basic reference symbols for the elements have 
been generally retained and only the indexes of the reference symbols have 
been sometimes changed. 
A major advantage of the variant embodiment illustrated in these two FIGS. 
9 and 10 is that the fibers have still less possibility of undesirably 
passing into the separation or parting joints 17 and 18, respectively. 
The variant embodiment illustrated in FIGS. 11 and 12 corresponds, in 
accordance with the invention, to the variant embodiment illustrated in 
FIGS. 7 and 8 with the sole difference that here the fiber feed passage or 
channel halves are not parts or components produced by injection molding 
but parts or components manufactured from sheet metal or metal plating. 
Accordingly, the elements or components are therefore generally 
conveniently indicated with the same reference characters in FIGS. 11 and 
12 as were used for the corresponding elements or components of the 
embodiment of FIGS. 7 and 8. 
The circular portions or regions indicated by reference characters A and B 
in FIGS. 4, 5 and 6 are indicated in FIGS. 7 to 12 by reference characters 
A.1 to A.3 and B.1 to B.3, respectively. 
FIGS. 13 to 16 also show a fiber feed passage or channel arrangement 3.2 
which can be manufactured from sheet metal or metal plating. This fiber 
feed passage or channel arrangement 3.2 comprises a first feed passage or 
channel half 10.3 and a second feed passage or channel half 11.3 together 
with the connecting or connector flange 12. The difference between the 
previous embodiments and the embodiment of these FIGS. 13 to 16 is such 
that each slot 15.2 and 16.2, respectively, is not disposed at right 
angles to the sidewalls 50 defining or bounding the feed passage or 
channel cross-section or internal fiber feed passage or channel 45 as was 
the case for the embodiments illustrated in FIGS. 4 to 12, but in this 
case is directed essentially parallel to these bounding sidewalls which in 
FIGS. 15 and 16 have however been conveniently designated by reference 
characters 38 and 39 (in such FIGS. 15 and 16 there are shown on an 
enlarged scale the details or regions indicated in FIG. 14 at the 
encircled portions labelled C and D). 
Such a slot or gap 15.2 and 16.2 is produced in that the connecting or 
connector flanges 36 and 37, respectively, are provided such that they are 
directed into the feed passage or channel cross-section i.e. into the 
internal fiber feed passage or channel 45. The connecting or connector 
flange 37 of the first half of the feed passage or channel 10.3 is bent or 
flexed in a direction essentially parallel to the neighboring or bounding 
sidewall 50 such that the other connecting or connector flange 36 of the 
second half of the feed passage or channel 11.3 is overlapped by the slot 
depth L. Through this overlapping of the connecting or connector flange 36 
by the connecting or connector flange 37, there are formed the slots or 
gaps 15.2 and 16.2, respectively. Each such slot 15.2 and 16.2 possesses 
the slot width W. This slot width W is formed, on the one hand, as already 
mentioned, by the connecting or connector flange 37 and, on the other 
hand, by the bounding sidewall portions 38 and 39, respectively, of the 
second half 11.3 of the fiber feed passage or channel 3.2. 
The advantage of this variant embodiment of FIGS. 14 to 16 is that the 
separation or parting joints 17 and 18 can hardly be reached by the 
fibers. 
FIGS. 17 and 18 show a further variant of the fiber feed passage or channel 
arrangement 3.2 illustrated in FIG. 14 in so far as here the connecting or 
connector flanges 36 and 37 are not arranged in the region of the middle 
of the fiber feed passage or channel arrangement 3.2 but are shifted 
towards a longitudinal wall 23 of such fiber feed passage or channel 
arrangement 3.2. Due to this arrangement, there is formed a respective 
slot or gap 15.2 and 16.2 in a location of the embodiment shown in FIGS. 
17 and 18 which has the advantage of being still further spaced from the 
flow of fibers than the slots 15.2 and 16.2 illustrated for the embodiment 
of FIGS. 15 and 16. These bounding sidewalls 38 and 39 of FIGS. 15 and 16 
correspond functionally to the bounding sidewalls 38.1 and 39.1 of FIGS. 
17 and 18, respectively. 
Since the arrangement of FIGS. 17 and 18 is a variant of the embodiment of 
FIGS. 14 to 16, the details enclosed in the encircled regions C and D of 
FIG. 14 have been shown in FIGS. 17 and 18 in the encircled regions there 
designated by reference characters C.1 and C.2. 
FIGS. 19 and 20 show a further variant embodiment in which the fiber feed 
passage or channel arrangement 3.3 comprises two fiber feed passage or 
channel halves 10.4 and 11.4. 
The difference here resides in that each slot, (see for instance, the slots 
15.3 and 16.3 of FIGS. 21 and 22), is arranged completely at the edge of 
the air flow or current transporting the fibers, in that each such slot or 
gap is defined or bounded in its width B, on the one hand, by the 
longitudinal wall 24 forming the feed passage or channel half 11.4, and, 
on the other hand, by feet 27 and 28, respectively, (FIGS. 21 and 22) 
provided at the sidewalls 25 and 26 of the first half 10.4 of the feed 
passage or channel 3.3. The longitudinal wall 24 is provided at its 
longitudinal sides or edges with bends or flexed portions 29 and 30 upon 
which the feet 27 and 28 of the sidewalls 25 and 26 are supported. The 
connection of the feet 27 and 28 with the bends or flexed portions 29 and 
30 of the longitudinal wall 24 can be accomplished by any suitable 
connecting or attachment technique, for example by soldering. 
FIG. 23 shows a variant embodiment of FIG. 20 in that here the fiber feed 
passage or channel arrangement 3.4 is formed by the longitudinal wall 24 
and a mirror-image arranged second longitudinal wall 31 together with two 
sidewalls 32 and 33. The second longitudinal wall 31 has feet 34 and 35 of 
the same dimensions arranged mirror-image to the feet 29 and 30 of the 
longitudinal wall 24. 
The sidewalls 32 and 33 have a thickness D which corresponds to the depth L 
of the slots or gaps 15.3 and 16.3, respectively, plus the width d of the 
bends or flexed portions or feet 29 and 30, respectively. These slots 15.3 
and 16.3 are arranged substantially at right angles to the corresponding 
sidewalls 25 and 26 or 32 and 33, respectively. 
If, now, during assembly of the fiber feed passage or channel 3.4, the 
longitudinal walls 24 and 31 are so joined to the sidewalls 32 and 33 that 
the feet 29 and 30 or 34 and 35 abut the end faces of the sidewalls 32 and 
33, and also the sidewalls 32 and 33 project inwardly of the feed passage 
or channel 3.4, then the slot 15.3 and 16.3, respectively is formed at the 
two end faces of the sidewalls 32 and 33. The longitudinal walls 24 and 31 
can be joined or connected by any kind of appropriate connector means, for 
example by soldering to the sidewalls 32 and 33. 
The advantage of this variant embodiment lies in the simple form or nature 
of the individual elements or components, and in that each slot or gap 
15.3 and 16.3, respectively, is located at the edge of the fiber feed flow 
or stream. 
Finally, it is mentioned that the respective slot or gap in FIGS. 4 to 8, 
11 and 12, and 20 to 23, seen in the direction of the associated slot or 
gap, is substantially straight, while the slots or gaps of FIGS. 9 and 10, 
seen in the same direction of viewing, are bent in a substantially 
boot-shape. The slots or gaps of FIGS. 14 to 18 are straight in the 
previously-mentioned sense, but due to the disposition of a portion 
thereof which extends essentially parallel to the associated sidewalls, 
seen in the direction of viewing towards the aforesaid sidewalls, such 
slots are also bent or flexed in a substantially boot-shaped fashion. 
Finally, the term "feed cross-section" or "passage or channel 
cross-section" or "cross-section of the fiber feed passage" as used herein 
refers to the interior of the fiber feed passage or channel arrangement 
but without the respective associated slots or gaps. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claims. ACCORDINGLY,