Indian Patents. 265406:TEXTILE MACHINE PRODUCING CROSS BOBBINS

Title of Invention	TEXTILE MACHINE PRODUCING CROSS BOBBINS
Abstract	In a textile machine producing cross-wound bobbins comprising at least one winding head, it is provided that the suction nozzle (12) which can be fed to a take-up bobbin (3) is connected, by means of a device (14), to a vacuum supply device, with which the suction effect can be changed and which can be adjusted by means of a controllable drive (15).

Full Text	FORM 2 THE PATENT ACT 1970 {39 of 1970) The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION TEXTILE MACHINE PRODUCING CROSS-WOUND BOBBINS 2. APPLICANT(S) a) Name b) Nationality c) Address SAURER GMBH & CO., KG. GERMAN Company LANDGRAFENSTRASSE 45, D--41069, MONCHENGLADBACH, GERMANY 3. PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : Description The invention relates to a textile machine producing cross-wound bobbins, comprising at least one winding head, which contains a suction nozzle which can be fed to a take-up bobbin and is connected to a vacuum supply device. A suction device of the type mentioned at the outset has the object of searching for and sucking in a thread end on the periphery of a take-up bobbin, while the take-up bobbin is rotated in the unwinding direction and then to place it in a thread connector. It is known in connection with winding machines (DE 32 25 379 Al) to provide a movable servicing apparatus for a plurality of winding heads, which produces thread connections, after a clearing cut has been carried out during a rewinding process. The servicing apparatus contains a suction nozzle, which can be fed to a take-up bobbin of the relevant winding head in order to search for the thread end on the take-up bobbin and then to draw it off. In order to load the suction nozzle with suction air, a so-called suction air metering mechanism is provided, which can connect the suction nozzle to a vacuum supply device by means of a control valve. The so called suction air dosing mechanism opens and closes the valve between the suction nozzle and suction air supply device. It is known in the case of an OE rotor spinning machine (DE 101 39 074 Al) to provide each spinning unit with a suction nozzle which can be fed to a take-up bobbin. The suction nozzle, which is to search for a thread end and draw it off, with the take-up bobbin being driven opposite to the winding direction, is connected to a vacuum supply device via a switchable valve. DE 102 57 804 Al, 102 01 533 Al and 101 39 074 Al also describe suction air supplies for suction nozzles for upper thread grasping. However, it is common to them all 2 that the suction air connection is switchable, in other words can be switched on and off. DE 17 85 293 A describes an adjustable screen in the main suction channel of the suction nozzle for the upper thread. This screen may also, apart from the completely open position and the completely closed position, temporarily also adopt a firm intermediate position. This intermediate position is only adjusted when the thread end has been grasped and, owing to the reduced vacuum, has the possibility of exiting through an elongated slot located in the suction nozzle in order to form a chord of the thread to be grasped by means of separate gripping members. It is also known (DE 196 50 934 Al) to connect a cop preparation device, which supplies prepared cops to a large number of winding heads of a winding machine to a suction air supply device by means of a blocking device. The cop preparation device consists of a stationary tube provided with an elongated slot, to which a cop can be fed. The blocking device arranged between the tube and a central suction air supply device contains a motor-driven screen, with which the suction air can not only be switched on and off, but can also be adjusted with respect to the strength of its effect. The invention is based on the object of improving the flexibility of a winding machine producing cross-wound bobbins of the type mentioned at the outset, in particular to optimise the take-up of the so-called upper thread from the cross-wound bobbin. This object is achieved in that a device is associated with the suction nozzle, with which device the suction effect of the suction nozzle can be changed and which can be adjusted by means of a controllable drive and which is adjustable to a predeterminable opening position as a function of the type of thread wound onto the take-up bobbin. 3 Different yarns react with different sensitivity to a vacuum, which is applied by the suction nozzle onto the yarns and onto the take-up bobbin. When different yarns or threads with different sensitivity to a vacuum are to be processed on one machine, the invention allows a differentiated adaptation of the effect of the vacuum at the individual winding heads with relatively simple means, without further elements of the winding head of the textile machine producing cross-wound bobbins or the textile machine producing the cross-wound bobbins having to be readjusted. In this case, the effect of the vacuum, which is applied by means of the suction nozzle to the bobbin and the thread piece to be found and drawn off thereby, can be adjusted independently of the vacuum which is required in other areas, even if a plurality of or all regions are connected to a common vacuum supply. It is thus possible to optimise the vacuum in the region of the respective suction nozzle without influencing other regions or winding heads in which a vacuum is also required from the vacuum supply. In this case it is possible for the first time owing to the invention, for example at a winding machine for rewinding cops, which has round cop magazines, which can be filled by hand, at its winding heads, to process a plurality of different yarn batches, which also clearly differ from one another with regard to the sensitivity of the yarns. In a development of the invention it is provided that the device for changing the suction effect contains an adjustable screen. The suction effect can be varied in wide ranges by means of a screen of this type. In a further development of the invention it is provided that the drive contains a stepping motor, which can be activated by means of a winding head computer. The stepping motor can bring the screen into any desired position and keep it there. Vacuum variations in the common vacuum supply may also be controlled in that the screen position is adapted to this changed vacuum and also then ensures a vacuum which remains constant and is adapted to the type of thread at the suction nozzle. 4 For this purpose, the vacuum in the common vacuum supply is monitored and fed to the winding head computer, which then activates the adaptation of the screen position. According to a refinement of the invention, a sensor is present for monitoring the grasping of the thread end and relaying the grasping signal to the winding head computer. The winding head computer has a circuit, which after absence of the grasping signal over a predeterminable period, activates the drive in such a way that the device increases the suction effect of the suction nozzle. It is thus ensured that a low vacuum adjusted, for example, because of a sensitive thread, at the nozzle opening, does not at times lead to the operator having to intervene to grasp the thread end, when automatic grasping is still possible with a stronger vacuum. The increase in the vacuum may take place gradually. "Gradually" is taken to mean here rising continually, or step-wise. The search for the thread can be assisted by a pitching movement of the suction nozzle in a small angle range. The search for the thread may also be interrupted by respective pivoting back of the suction nozzle by a larger pivoting path, optionally into the base position. In the case of a repeated attempt, the suction effect is then increased, in each case, by a changed screen position. In a further development of the invention it is provided that the device for changing the suction effect can be adjusted by means of the drive in predetermined time sequences between predetermined opening positions. In this manner, it is possible to bring about a rapid rise and ebbing away of the suction air flow, with which the suction nozzle acts on the take-up bobbin when searching for and drawing off a thread end. It is thus possible to facilitate the finding of the thread ends rolled into the bobbin. Moreover, an influencing of the intensity of the action on the thread can be brought about over and above the opening position of the screen by the frequency of the pulses. 5 The invention will be described in more detail hereinafter with the aid of an embodiment shown in the drawing. The figure shows a schematic view of a winding head of a textile machine producing cross-wound bobbins, in the present case a winding machine, in which cops are rewound to form cross-wound bobbins and which conventionally has a large number of winding heads of this type. Alternatively, the winding heads according to the invention may also be winding heads, which are arranged in connection with a spinning device. At each winding head, a thread 2 is drawn off from a spinning bobbin 1, a so-called cop and wound as a cross-wound bobbin, the so-called take-up bobbin 3. A cross-wound bobbin takes-up the length of a large number of spinning heads 1. During rewinding, the thread 2 is monitored for yarn defects, in that it runs through an optical or capacitive electronic clearer 4. If the clearer 4 finds a defect, the thread 2 is cut. The defective thread length is separated off, after which the thread ends produced are connected to one another again. This takes place, for example, by means of a splicer 5. The take-up bobbin 3 is held in a creel 6, which can be pivoted about an axle 7 in such a way that the take-up bobbin 3 rests during the entire bobbin travel with its periphery on a winding roller 8, by which it is driven by means of friction. The winding roller 8 is provided with a drive motor, not shown, which can drive it both in the winding direction (identified by the arrow) and in the unwinding direction. When the clearer 4 severs the thread 2 or the thread breaks for other reasons, the end of the thread connected to the take-up bobbin is still wound onto the take-up bobbin and then rests somewhere on the periphery of this take-up bobbin 3. The end connected to the spinning bobbin 1 is held in a thread tensioning device 9. In order 6 to produce the thread connection again, the two thread ends to be connected have to be placed in the thread connection device, i.e. in the splicer 5. For this purpose, a lower thread gripper 10, which can be pivoted about an axle 11, is fed to the lower thread which is running to the thread tensioning device 9 and coming from the spinning bobbin 1. A suction nozzle 12, which can be pivoted about an axle 13, is fed to the take-up bobbin 3. In order to find the thread end at the periphery of the take-up bobbin 3, to take it up and draw it off, the take-up bobbin 3 is driven by the winding roller 8 counter to the winding direction. The suction gripper 12 pivots, after grasping the thread end, with the thread drawn off from the take-up bobbin, the so-called upper thread, back into the position shown and inserts the thread into the splicer 5. The suction nozzle 12 is a bent, tubular body, which at its free end forms a flat nozzle, which approximately corresponds to the width of the take-up bobbin 3. The suction nozzle is connected to a vacuum supply device in the region of its rotary axle 13. For this purpose, the rotary axle 13 is designed, for example, as a tubular lug, which is located as an extension on a vacuum supply device extending along the machine. In order to be able to adjust the suction effect of the suction nozzle according to the invention, a screen 14, with which the opening cross-section and therefore the strength of the suction air flow and the suction effect of the suction nozzle 12 can be adjusted, is associated with the tubular lug 13, which also forms the rotary axle. The screen 14 can be pivoted by means of a drive 15, which has a stepping motor. The screen 14 can be adjusted by means of the drive in any desired position. The stepping motor is activated by means of a winding head computer 16 which also controls the remaining elements of the winding head, i.e. the clearer 4, the splicer 5, the drive of the winding roller 8, the thread tensioning device 9 and the drives, 7 which bring about the pivotal movement of the thread gripper 10 and the suction nozzle 12. An input unit 17, with which the operating conditions can be input, and in particular, the desired opening position of the screen 14, which is adjusted by the motor drive, is associated with the winding head computer 16. This can also take place from the central position of the winding machine. For this purpose, the winding head computer is connected, as shown in the drawing, to a data bus of the machine. The motor drive can provide that the screen 14 is opened and closed at certain times, and that the screen 14 adopts a certain position in the opening position and therefore clears a predeterminable cross-section. In one embodiment of the invention it is provided that the screen 14 is adjusted to an opening cross-section, when the suction nozzle 12 is fed to the take-up bobbin 3, which cross-section differs from the opening cross-section, to which the screen is adjusted while the suction nozzle 12 moves away again with the located thread from the take-up bobbin 3, in order to place the upper thread in the thread connector (splicer). The change-over between the opening cross-sections is controlled, in this case, by a sensor 18, which is arranged inside the suction nozzle 12 and which recognises whether the suction nozzle has found the thread end of the take-up bobbin 3 and taken it up. Once grasping of the thread end has been recognised, the vacuum is reduced by means of the screen position, as the stronger vacuum required for searching for the thread no longer has to be applied. Moreover, when the sensor 18 does not report the grasping of the thread to the winding head computer 16 over a predeterminable time, the screen 14 can be opened further for more intensive searching for the thread. Alternatively, the further opening of the screen 14 may take place step-wise or continuously. In a different embodiment, it is provided that the screen 14, when the suction gripper 12 is fed to the take-up bobbin 3, is moved in a rapidly alternating manner back and forth between an opened or closed position or between a further opened and less opened position, so a suction air flow which ebbs away and rises and which acts on the periphery of the take-up bobbin 3, is obtained. This movement of the 8 screen 14 is caused by corresponding activation of the drive 15 preferably designed as a stepping motor and then reciprocating. The rise and ebbing away of the suction air flow is expediently carried out only for as long as the suction gripper is fed to the take-up bobbin 3. When it has been recognised by the sensor 18 that a thread end has been found and taken up, the screen 14 is held in a predetermined position, with which a predetermined suction effect is associated. A vacuum monitoring device, not shown, in the common vacuum supply is coupled to the winding head computer and transmits the pressure data. In this manner, the screen position may also be adapted depending on the vacuum in the vacuum supply. The cross-section which is to be cleared by the screen and is required individually, has to be determined or optimised empirically as a function of the vacuum in the vacuum supply and the vacuum required at the suction nozzle opening. In this case, the screen positions have to be determined particularly precisely close to the closed position, as no significant vacuum changes occur yet in the region of the suction nozzle opening in the region of the open position. This results above all from the fact that a significant pressure reduction only occurs with an increasing falling below of the cross-section of the suction nozzle opening. 9 We Claims 1. Textile machine producing cross-wound bobbins, comprising winding heads which are arranged next to one another and contain a suction nozzle, in each case, which can be fed to a take-up bobbin and which are connected to a common vacuum supply device, characterised in that a device (14) is associated with the suction nozzle (12), with which device the suction effect of the suction nozzle (12) can be changed and which can be adjusted by means of a controllable drive (15) and which can be adjusted to a predetermined opening position as a function of the type of thread wound onto the take-up bobbin. 2. Textile machine producing cross-wound bobbins according to claim 1, characterised in that the device for changing the suction effect contains an adjustable screen (14). 3. Textile machine producing cross-wound bobbins according to claim 1 or 2, characterised in that the drive (15) contains a stepping motor, which can be activated by means of a winding head computer (16). 4. Textile machine producing cross-wound bobbins according to claim 1, characterised in that the opening position can be adjusted as a function of the current vacuum in the vacuum supply device. 5. Textile machine producing cross-wound bobbins according to any one of claims 1 to 4, characterised in that a sensor (18) for monitoring the grasping of the thread end and relaying the grasping signal to the winding head computer (16) is present and in that the winding head computer has a circuit, which activates the drive (15) when the detection signal is absent over a predeterminable period in such a way that the device (14) increases the suction effect of the suction nozzle (12). 10 6. Textile machine producing cross-wound bobbins according to claim 5, characterised in that the circuit is set up in such a way that it gradually increases the suction effect of the suction nozzle. 7. Textile machine producing cross-wound bobbins according to claim 6, characterised in that the circuit is set up in such a way that it increases the suction effect of the suction nozzle step-wise. 8. Textile machine producing cross-wound bobbins according to any one of claims 1 to 3, characterised in that the device (14) can be adjusted to change the suction effect by means of the drive (15) in predetermined time sequences between predetermined opening positions. Dated this 3rd day of March, 2006 11 Abstract In a textile machine producing cross-wound bobbins comprising at least one winding head, it is provided that the suction nozzle (12) which can be fed to a take-up bobbin (3) is connected, by means of a device (14), to a vacuum supply device, with which the suction effect can be changed and which can be adjusted by means of a controllable drive (15). To The Controller of Patent Office The Patent Office Mumbai 12

Full Text

FORM 2
THE PATENT ACT 1970 {39 of 1970)
The Patents Rules, 2003 COMPLETE SPECIFICATION
(See Section 10, and rule 13)
1. TITLE OF INVENTION
TEXTILE MACHINE PRODUCING CROSS-WOUND BOBBINS

2. APPLICANT(S)
a) Name
b) Nationality
c) Address

SAURER GMBH & CO., KG. GERMAN Company LANDGRAFENSTRASSE 45,
D--41069, MONCHENGLADBACH, GERMANY

3. PREAMBLE TO THE DESCRIPTION
The following specification particularly describes the invention and the manner in which it is to be performed :

Description
The invention relates to a textile machine producing cross-wound bobbins, comprising at least one winding head, which contains a suction nozzle which can be fed to a take-up bobbin and is connected to a vacuum supply device.
A suction device of the type mentioned at the outset has the object of searching for and sucking in a thread end on the periphery of a take-up bobbin, while the take-up bobbin is rotated in the unwinding direction and then to place it in a thread connector.
It is known in connection with winding machines (DE 32 25 379 Al) to provide a movable servicing apparatus for a plurality of winding heads, which produces thread connections, after a clearing cut has been carried out during a rewinding process. The servicing apparatus contains a suction nozzle, which can be fed to a take-up bobbin of the relevant winding head in order to search for the thread end on the take-up bobbin and then to draw it off. In order to load the suction nozzle with suction air, a so-called suction air metering mechanism is provided, which can connect the suction nozzle to a vacuum supply device by means of a control valve. The so called suction air dosing mechanism opens and closes the valve between the suction nozzle and suction air supply device.
It is known in the case of an OE rotor spinning machine (DE 101 39 074 Al) to provide each spinning unit with a suction nozzle which can be fed to a take-up bobbin. The suction nozzle, which is to search for a thread end and draw it off, with the take-up bobbin being driven opposite to the winding direction, is connected to a vacuum supply device via a switchable valve.
DE 102 57 804 Al, 102 01 533 Al and 101 39 074 Al also describe suction air supplies for suction nozzles for upper thread grasping. However, it is common to them all
2

that the suction air connection is switchable, in other words can be switched on and off.
DE 17 85 293 A describes an adjustable screen in the main suction channel of the suction nozzle for the upper thread. This screen may also, apart from the completely open position and the completely closed position, temporarily also adopt a firm intermediate position. This intermediate position is only adjusted when the thread end has been grasped and, owing to the reduced vacuum, has the possibility of exiting through an elongated slot located in the suction nozzle in order to form a chord of the thread to be grasped by means of separate gripping members.
It is also known (DE 196 50 934 Al) to connect a cop preparation device, which supplies prepared cops to a large number of winding heads of a winding machine to a suction air supply device by means of a blocking device. The cop preparation device consists of a stationary tube provided with an elongated slot, to which a cop can be fed. The blocking device arranged between the tube and a central suction air supply device contains a motor-driven screen, with which the suction air can not only be switched on and off, but can also be adjusted with respect to the strength of its effect.
The invention is based on the object of improving the flexibility of a winding machine producing cross-wound bobbins of the type mentioned at the outset, in particular to optimise the take-up of the so-called upper thread from the cross-wound bobbin.
This object is achieved in that a device is associated with the suction nozzle, with which device the suction effect of the suction nozzle can be changed and which can be adjusted by means of a controllable drive and which is adjustable to a predeterminable opening position as a function of the type of thread wound onto the take-up bobbin.
3

Different yarns react with different sensitivity to a vacuum, which is applied by the suction nozzle onto the yarns and onto the take-up bobbin. When different yarns or threads with different sensitivity to a vacuum are to be processed on one machine, the invention allows a differentiated adaptation of the effect of the vacuum at the individual winding heads with relatively simple means, without further elements of the winding head of the textile machine producing cross-wound bobbins or the textile machine producing the cross-wound bobbins having to be readjusted. In this case, the effect of the vacuum, which is applied by means of the suction nozzle to the bobbin and the thread piece to be found and drawn off thereby, can be adjusted independently of the vacuum which is required in other areas, even if a plurality of or all regions are connected to a common vacuum supply. It is thus possible to optimise the vacuum in the region of the respective suction nozzle without influencing other regions or winding heads in which a vacuum is also required from the vacuum supply.
In this case it is possible for the first time owing to the invention, for example at a winding machine for rewinding cops, which has round cop magazines, which can be filled by hand, at its winding heads, to process a plurality of different yarn batches, which also clearly differ from one another with regard to the sensitivity of the yarns.
In a development of the invention it is provided that the device for changing the suction effect contains an adjustable screen. The suction effect can be varied in wide ranges by means of a screen of this type.
In a further development of the invention it is provided that the drive contains a stepping motor, which can be activated by means of a winding head computer. The stepping motor can bring the screen into any desired position and keep it there.
Vacuum variations in the common vacuum supply may also be controlled in that the screen position is adapted to this changed vacuum and also then ensures a vacuum which remains constant and is adapted to the type of thread at the suction nozzle.
4

For this purpose, the vacuum in the common vacuum supply is monitored and fed to the winding head computer, which then activates the adaptation of the screen position.
According to a refinement of the invention, a sensor is present for monitoring the grasping of the thread end and relaying the grasping signal to the winding head computer. The winding head computer has a circuit, which after absence of the grasping signal over a predeterminable period, activates the drive in such a way that the device increases the suction effect of the suction nozzle. It is thus ensured that a low vacuum adjusted, for example, because of a sensitive thread, at the nozzle opening, does not at times lead to the operator having to intervene to grasp the thread end, when automatic grasping is still possible with a stronger vacuum. The increase in the vacuum may take place gradually. "Gradually" is taken to mean here rising continually, or step-wise. The search for the thread can be assisted by a pitching movement of the suction nozzle in a small angle range. The search for the thread may also be interrupted by respective pivoting back of the suction nozzle by a larger pivoting path, optionally into the base position. In the case of a repeated attempt, the suction effect is then increased, in each case, by a changed screen position.
In a further development of the invention it is provided that the device for changing the suction effect can be adjusted by means of the drive in predetermined time sequences between predetermined opening positions. In this manner, it is possible to bring about a rapid rise and ebbing away of the suction air flow, with which the suction nozzle acts on the take-up bobbin when searching for and drawing off a thread end. It is thus possible to facilitate the finding of the thread ends rolled into the bobbin. Moreover, an influencing of the intensity of the action on the thread can be brought about over and above the opening position of the screen by the frequency of the pulses.
5

The invention will be described in more detail hereinafter with the aid of an embodiment shown in the drawing.
The figure shows a schematic view of a winding head of a textile machine producing cross-wound bobbins, in the present case a winding machine, in which cops are rewound to form cross-wound bobbins and which conventionally has a large number of winding heads of this type. Alternatively, the winding heads according to the invention may also be winding heads, which are arranged in connection with a spinning device.
At each winding head, a thread 2 is drawn off from a spinning bobbin 1, a so-called cop and wound as a cross-wound bobbin, the so-called take-up bobbin 3. A cross-wound bobbin takes-up the length of a large number of spinning heads 1.
During rewinding, the thread 2 is monitored for yarn defects, in that it runs through an optical or capacitive electronic clearer 4.
If the clearer 4 finds a defect, the thread 2 is cut. The defective thread length is separated off, after which the thread ends produced are connected to one another again. This takes place, for example, by means of a splicer 5.
The take-up bobbin 3 is held in a creel 6, which can be pivoted about an axle 7 in such a way that the take-up bobbin 3 rests during the entire bobbin travel with its periphery on a winding roller 8, by which it is driven by means of friction. The winding roller 8 is provided with a drive motor, not shown, which can drive it both in the winding direction (identified by the arrow) and in the unwinding direction.
When the clearer 4 severs the thread 2 or the thread breaks for other reasons, the end of the thread connected to the take-up bobbin is still wound onto the take-up bobbin and then rests somewhere on the periphery of this take-up bobbin 3. The end connected to the spinning bobbin 1 is held in a thread tensioning device 9. In order
6

to produce the thread connection again, the two thread ends to be connected have to be placed in the thread connection device, i.e. in the splicer 5.
For this purpose, a lower thread gripper 10, which can be pivoted about an axle 11, is fed to the lower thread which is running to the thread tensioning device 9 and coming from the spinning bobbin 1. A suction nozzle 12, which can be pivoted about an axle 13, is fed to the take-up bobbin 3. In order to find the thread end at the periphery of the take-up bobbin 3, to take it up and draw it off, the take-up bobbin 3 is driven by the winding roller 8 counter to the winding direction. The suction gripper 12 pivots, after grasping the thread end, with the thread drawn off from the take-up bobbin, the so-called upper thread, back into the position shown and inserts the thread into the splicer 5.
The suction nozzle 12 is a bent, tubular body, which at its free end forms a flat nozzle, which approximately corresponds to the width of the take-up bobbin 3. The suction nozzle is connected to a vacuum supply device in the region of its rotary axle 13. For this purpose, the rotary axle 13 is designed, for example, as a tubular lug, which is located as an extension on a vacuum supply device extending along the machine.
In order to be able to adjust the suction effect of the suction nozzle according to the invention, a screen 14, with which the opening cross-section and therefore the strength of the suction air flow and the suction effect of the suction nozzle 12 can be adjusted, is associated with the tubular lug 13, which also forms the rotary axle.
The screen 14 can be pivoted by means of a drive 15, which has a stepping motor. The screen 14 can be adjusted by means of the drive in any desired position.
The stepping motor is activated by means of a winding head computer 16 which also controls the remaining elements of the winding head, i.e. the clearer 4, the splicer 5, the drive of the winding roller 8, the thread tensioning device 9 and the drives,
7

which bring about the pivotal movement of the thread gripper 10 and the suction nozzle 12. An input unit 17, with which the operating conditions can be input, and in particular, the desired opening position of the screen 14, which is adjusted by the motor drive, is associated with the winding head computer 16. This can also take place from the central position of the winding machine. For this purpose, the winding head computer is connected, as shown in the drawing, to a data bus of the machine. The motor drive can provide that the screen 14 is opened and closed at certain times, and that the screen 14 adopts a certain position in the opening position and therefore clears a predeterminable cross-section. In one embodiment of the invention it is provided that the screen 14 is adjusted to an opening cross-section, when the suction nozzle 12 is fed to the take-up bobbin 3, which cross-section differs from the opening cross-section, to which the screen is adjusted while the suction nozzle 12 moves away again with the located thread from the take-up bobbin 3, in order to place the upper thread in the thread connector (splicer). The change-over between the opening cross-sections is controlled, in this case, by a sensor 18, which is arranged inside the suction nozzle 12 and which recognises whether the suction nozzle has found the thread end of the take-up bobbin 3 and taken it up. Once grasping of the thread end has been recognised, the vacuum is reduced by means of the screen position, as the stronger vacuum required for searching for the thread no longer has to be applied.
Moreover, when the sensor 18 does not report the grasping of the thread to the winding head computer 16 over a predeterminable time, the screen 14 can be opened further for more intensive searching for the thread. Alternatively, the further opening of the screen 14 may take place step-wise or continuously.
In a different embodiment, it is provided that the screen 14, when the suction gripper 12 is fed to the take-up bobbin 3, is moved in a rapidly alternating manner back and forth between an opened or closed position or between a further opened and less opened position, so a suction air flow which ebbs away and rises and which acts on the periphery of the take-up bobbin 3, is obtained. This movement of the
8

screen 14 is caused by corresponding activation of the drive 15 preferably designed as a stepping motor and then reciprocating. The rise and ebbing away of the suction air flow is expediently carried out only for as long as the suction gripper is fed to the take-up bobbin 3. When it has been recognised by the sensor 18 that a thread end has been found and taken up, the screen 14 is held in a predetermined position, with which a predetermined suction effect is associated.
A vacuum monitoring device, not shown, in the common vacuum supply is coupled to the winding head computer and transmits the pressure data. In this manner, the screen position may also be adapted depending on the vacuum in the vacuum supply.
The cross-section which is to be cleared by the screen and is required individually, has to be determined or optimised empirically as a function of the vacuum in the vacuum supply and the vacuum required at the suction nozzle opening. In this case, the screen positions have to be determined particularly precisely close to the closed position, as no significant vacuum changes occur yet in the region of the suction nozzle opening in the region of the open position. This results above all from the fact that a significant pressure reduction only occurs with an increasing falling below of the cross-section of the suction nozzle opening.
9

We Claims
1. Textile machine producing cross-wound bobbins, comprising winding heads which are arranged next to one another and contain a suction nozzle, in each case, which can be fed to a take-up bobbin and which are connected to a common vacuum supply device, characterised in that a device (14) is associated with the suction nozzle (12), with which device the suction effect of the suction nozzle (12) can be changed and which can be adjusted by means of a controllable drive (15) and which can be adjusted to a predetermined opening position as a function of the type of thread wound onto the take-up bobbin.
2. Textile machine producing cross-wound bobbins according to claim 1, characterised in that the device for changing the suction effect contains an adjustable screen (14).
3. Textile machine producing cross-wound bobbins according to claim 1 or 2, characterised in that the drive (15) contains a stepping motor, which can be activated by means of a winding head computer (16).
4. Textile machine producing cross-wound bobbins according to claim 1, characterised in that the opening position can be adjusted as a function of the current vacuum in the vacuum supply device.
5. Textile machine producing cross-wound bobbins according to any one of claims 1 to 4, characterised in that a sensor (18) for monitoring the grasping of the thread end and relaying the grasping signal to the winding head computer (16) is present and in that the winding head computer has a circuit, which activates the drive (15) when the detection signal is absent over a predeterminable period in such a way that the device (14) increases the suction effect of the suction nozzle (12).
10

6. Textile machine producing cross-wound bobbins according to claim 5, characterised in that the circuit is set up in such a way that it gradually increases the suction effect of the suction nozzle.
7. Textile machine producing cross-wound bobbins according to claim 6, characterised in that the circuit is set up in such a way that it increases the suction effect of the suction nozzle step-wise.
8. Textile machine producing cross-wound bobbins according to any one of claims 1 to 3, characterised in that the device (14) can be adjusted to change the suction effect by means of the drive (15) in predetermined time sequences between predetermined opening positions.
Dated this 3rd day of March, 2006

11

Abstract
In a textile machine producing cross-wound bobbins comprising at least one winding head, it is provided that the suction nozzle (12) which can be fed to a take-up bobbin (3) is connected, by means of a device (14), to a vacuum supply device, with which the suction effect can be changed and which can be adjusted by means of a controllable drive (15).
To
The Controller of Patent Office
The Patent Office
Mumbai
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TEXTILE MACHINE PRODUCING CROSS BOBBINS

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