Thread suction device

The thread suction device has means for bunching a plurality of threads together adjacent to a nozzle opening so that the threads can be simultaneously and uniformly drawn into the suction nozzle. In one embodiment, the nozzle is moved in order to bunch up the thread prior to drawing in of the threads. In another embodiment, a guide on the nozzle is moved in order to bunch the threads up against the nozzle prior to drawing in of the threads.

This invention relates to a thread suction device. More particularly, this 
invention relates to a thread suction device for use in a draw-winding or 
spin-draw-winding process. 
As is known, various types of thread suction devices come into use in 
processes for treating endless filaments, for example, in draw-winding or 
spin-draw-winding processes. In many of the earlier processes, the suction 
devices were used to treat only one thread at a given spinning position. 
In the more recent past, the treatment of several threads in a spinning 
position has been known and, at least, in the future should continue to be 
used. 
As is known, thread suction devices for removing threads usually operate in 
cooperation with thread monitoring elements. In this way, upon the 
occurrence of a disturbance at a subsequent processing location on a 
thread path, the thread feed to that location can be interrupted as 
quickly as possible. However, in the case of a multi-thread arrangement, 
the use of a separate suction removal device for each thread becomes 
expensive. 
Accordingly, it is an object of the invention to provide a thread suction 
device which can be economically employed for a multi-thread arrangement. 
It is another object of the invention to provide a relatively simple thread 
suction device for use in a multi-thread arrangement. 
Briefly, the invention provides a thread suction device which is comprised 
of a thread suction nozzle for disposition in perpendicular relation to a 
thread path having a plurality of threads passing therethrough and means 
for displacing at least two of the threads into a common position adjacent 
to an opening of the nozzle facing the thread path. 
The operation of the thread suction device is such that all of the threads 
in the thread path can be removed by an intensive suction simultaneously 
and uniformly. Further, the thread suction device can be used in a 
particularly economic manner since the device occupies a relatively small 
space and may operate, for example pneumatically. 
The thread suction device can also be used with advantage for individual 
threads in the event that vibrations in a thread cannot be avoided at the 
suction removal or take-up position.

Referring to FIGS. 1 and 2, the thread suction device includes a head 
portion 1 and a diffusor portion 2. 
The head portion 1 is mounted in a bore 3 of a machine frame 4 via a flange 
5. As indicated, a pair of screws 6 pass through the flange 5 to secure 
the head portion 1 to the machine frame 4. 
The diffusor portion 2 is threaded into the machine frame 4 by means of a 
thread 7. In addition, the diffusor portion 2 abuts the head portion 1 at 
a location within the frame 4 while an O-ring 8 is positioned in the end 
of the head portion 1 to seal against the diffusor portion 2 to prevent 
the leakage of air. 
As indicated, the head portion 1 includes a stationary cylinder portion 14 
which is integral with the flange 5 and a cylindrical cover 15 which is 
fixedly secured to the cylinder portion 14. In addition, a thread suction 
nozzle in the form of a one way pressurable pneumatic piston 9 is slidably 
mounted within the head portion 1 and is secured against rotation in any 
suitable manner. The piston 9 has a flow channel 10 with an opening 
directed towards a thread path in which a plurality of threads 11 travel. 
In addition, an orifice portion 12 of ceramic material is fixed in the 
opening of the flow channel 10 to define an opening for the nozzle facing 
the thread path. As indicated, the nozzle 9 also has a hollow cylindrical 
extension 13 which continues the flow channel 10 coaxially to the 
passageway through the diffusor portion 2. 
A means is also provided for displacing the threads 11 in the thread path 
into a common take-up position adjacent to the orifice portion 12 forming 
the nozzle opening. This means is connected with the nozzle 9 so as to 
move the nozzle 9 between a rest position as shown in FIG. 1 and a thread 
take-up position (not shown). Movement of the nozzle 9 to the thread 
take-up position causes the nozzle 9 to bunch the threads 11 in the thread 
path into the common take-up position. 
As indicated, the means for displacing the nozzle 9 includes a pressure air 
source 19, a two/two-way valve 20 for controlling the feeding of 
pressurized air from the source 19 and a connecting portion 22 which 
communicates with channels 23, 24 in the machine frame 4. The channels 23, 
24, in turn, communicate with a distributor space 25 defined by the 
machine frame 4, head portion 1 and diffusor portion 2 in order to deliver 
the pressurized air thereto. This distributor space 25, in turn, 
communicates via a plurality of channels 16 in the head portion 1 with a 
space between the head portion 1 and the nozzle 9 in order to move the 
nozzle 9 relative to the head portion 1 into a take-up position (not 
shown). 
During movement, the piston 9 is guided in the cylinder portion 14 and 
cylinder cover 15. The pressure air acts primarily on an annular surface 
17 on the piston 9 whereby, after lifting off of the piston 9, the annular 
surface resulting from the difference of the diameter D (i.e. the inside 
diameter of the cylinder 14) and the diameter d (i.e. the outside diameter 
of the extension 13) is pressurized. 
The means for displacing the piston also includes a helical spring 18 which 
is loaded under pressure and which serves for returning the piston into 
the initial rest position illustrated in FIG. 1. 
The thread suction device also includes a means for drawing the thread 11 
in the take-up position into the nozzle 9 through the orifice portion 12. 
This means may include a separate source (not shown) of vacuum pressure 
downstream of the diffusor portion 2 which is sufficient to create a 
suction force for the air stream S. Alternatively, this means may be 
provided by bores in the diffusor portion 2 which are connected with the 
distributor space 125 in such a manner that upon flow of the pressure air 
through the channel (not shown) in the diffusor portion 2 an under 
pressure is produced in the channel 10. In such a case, the valve 20 is 
used since the venting required for the return movement of the piston 9 
can occur through the non-illustrated channels. 
In the case use is made of a separate vacuum source, the non-illustrated 
channels are not present. However, a three/two-way valve 21 is used to 
permit venting for the return movement of the piston 9. 
Of note, other commercially available venturi nozzles can be used for the 
diffusor portion 2 and the channel 10 can be adapted to these nozzles. 
Referring to FIGS. 1 and 2, the thread suction nozzle also includes a 
thread guide in the form of a hollow cylindrical extension 28 on the 
piston 9 which is provided with slits 27 to define the thread path for the 
threads 11. This extension 28 also serves for the diversion of the air 
stream before entry of the air into the orifice portion 12. 
The thread suction device is also provided with seals 29, 30, 31 in order 
to prevent the escape of leakage air. Further, the diffusor portion 2 is 
connected with a hose 32 which leads directly or via a suction source to a 
receiving container (not shown). 
In operation, in order to remove the threads 11, the valve 20 is brought 
into an appropriate condition for a through-flow of air from the input P 
to the output A of the valve. Thus, air is introduced into the thread 
suction device so that the nozzle 9 is moved one stroke against the cover 
15. In this regard, the piston 9 is provided with an O-ring 26 for 
abutting against the cover 15. During this time, the orifice portion 12 
pushes the threads 11 together into a single bunched or bundled thread in 
a common take-up position (not shown). In addition, an air stream S is 
produced, i.e. by separate suction means or by suitable channels in the 
piston 9. After a cutter device (not shown) provided downstream in the 
thread movement direction F has cut the threads 11, the threads 11 are 
then sucked away simultaneously and practically with the same suction 
intensity. 
In the event that a separate suction source is used to create the air 
stream S, this source is set in operation simultaneously with the movement 
of the valve 21 for the through flow of pressure air from the input P to 
the output A. 
Referring to FIGS. 3 and 4, wherein like reference characters indicate like 
parts as above, the thread suction device may alternatively be constructed 
with a fixed nozzle and with a movable guide. To this end, the device has 
a head portion 100 which is mounted in a bore 3 of the machine frame 4 and 
which is secured to the machine frame 4 by a pair of screws 102 which pass 
through a flange 101 of the head portion 100. In addition, the head 
portion 100 has a stationary cylinder portion 103 with a cylindrical cover 
104 secured thereto. The cylinder portion 103 includes a coaxial stem 106 
on which a pneumatic piston 105 is slidably mounted. This piston 105 is 
secured against rotation and is biased by a spring 108 into a rest 
position. 
The piston 105 has an extension 113 which projects outwardly to form a 
guide. The extension 113 is of hollow cylindrical shape and has cut-outs 
114 to define a thread path for the threads 11. In addition, as indicated 
in FIG. 4, the extension 113 has a catch 119 at one end for engaging and 
bunching up the threads 11 during movement of the piston 105 to a take-up 
position (not shown). 
The means for displacing the piston 105 is pneumatically operated. As 
above, this means includes a source of pressurized air 19, a valve 20 (or 
21) and a connecting piece 22. As indicated, the connecting piece 22 
communicates with channels 23, 24 in the machine frame 4 to direct 
pressurized air into a distribution space 25. In addition, the channel 23 
communicates via channels 117, 118 in the head portion 100 with a space 
between the piston 105 and the head portion 100. This space is defined in 
part by an annular surface 107 on the piston 105. 
The stroke of the piston 105 is limited by an abutment 109 on the cover 104 
and an abutment 110 on the piston 105. 
In order to avoid the escape of pressure air which is required for the 
movement of the piston 105 into the space in which the spring 108 is 
located and to the atmosphere, appropriate O-ring seals 111, 112 are 
provided about the pressure receiving space. 
In operation, the valve 20 is switched on so that air can be supplied to 
the space defined, in part, by the annular surface 107 of the piston 105. 
The piston 105 is then moved against the force of the spring 108 until the 
abutment 110 abuts against the head portion 100. Because of this movement, 
the extension 113 is also forced to move. Hence, the catch 119 engages and 
bunches the threads 11 together until all of the threads abut the opening 
piece 116. The subsequently cut threads can then be drawn away together 
and with practically the same intensity. 
After the return of the valve 20 into the position shown in FIG. 3, the 
channels 23, 117, 118 are again vented so that the piston 105 is returned 
to the initial rest position indicated in FIG. 3 via the spring 108. 
Operation of the thread suction device with the valve 21 occurs in a 
similar manner as described above. 
Of note, the air in the space in which the spring 18 of FIG. 1 or the 
spring 108 of FIG. 3 is located may escape into the atmosphere during the 
piston stroke through an opening (not shown) in the head portion 1, 100, 
respectively. 
The invention thus provides a thread suction device of relatively simple 
construction which can be used for removing a plurality of cut threads 
simultaneously under a substantially uniform suction force. 
The invention further provides a thread suction device which can be 
automatically actuated in order to gather in a plurality of cut threads, 
for example in a spinning position of a thread processing machine.