Title of Invention

A METHOD AND AN APPARATUS FOR PREPARING A LAP END OF A WEB

Abstract The invention relates to a method and an apparatus for performing the process of preparing a lap end (E) of a web (B) for subsequent further processing of the web. In known apparatuses for the preparation of the lap end of a wound lap (w) the web (B) is usually held in one or two clamping positions and is severed. The actual severing line is not clearly definable. In order to improve this situation it is proposed that the web (B) is clamped over its width and the free end (E) projecting over the clamping position (K) is severed immediately downstream of the clamping position by means of a compressed air stream which is produced over the width of the web (B). This compressed air stream can be produced by a compressed air nozzle (32) whose outlet opening (33) is arranged adjacent to and directly on the outlet side of the clamping apparatus (K). FIGURE 1
Full Text

PREPARATION OF A LAP END OF A WEB
The invention relates to a method and an apparatus for performing the process of preparing the lap end of a web for subsequent further processing.
For the automatic piecing of the lap end of a wound lap of a combing machine, for example, it is necessary that the lap end is prepared in a respective manner in order to prevent thin or thick places in the area of the piecing site during the subsequent piecing process on a trailing lap end. Such a piecing of a newly supplied wound lap can also be used in combing preparation. The thus prepared lap should be provided, as seen in the longitudinal direction of the unwinding direction, with a severing edge which is situated on an approximately even severing line, with the lap end running out in an approximately pointed manner. This means that the lap end is slightly thinned out as compared with the web.
Such a device is known from EP-Al-482 475, with the lap end of the wound lap which rests on the lap rollers being prepared by a preparation device which is arranged between the two lap rollers. In this process the end still resting on the wound lap is sucked off by means of a suction device and transferred to the zone of a clamping device. During this process the wound lap is rotated until it is determined by means of a sensor that the sucked-off lap end is located with a sufficient length in the zone of the clamping device. As soon as this state is reached, the further rotation of the wound lap is prevented by stopping the lap rollers and the clamping device is shut. The wound lap is then rotated in the reverse direction by reversing the drive of the lap rollers while the clamping device is closed, with the clamping device clamping the web over its entire width. As a result of the clamping, the lap end is

pulled apart or severed between the clamping position and the bearing point of the wound lap on the rear lap roller.
The severed end located below the clamping position is sucked off and disposed of by means of a suction device after the opening of the clamping device.
With this device a mostly well-prepared lap end is obtained which is suitable for a subsequent automatic piecing process.
It has already occurred, however, particularly when fibre material with relatively short fibres (short staple) has to be processed, that the distance between the clamping position of the clamping device and the bearing point of the wound lap on the rear lap roller is too large in order to obtain a defined severing edge.
This means that the severing line or edge can be located at any position, and not a precisely predetermined one, between the said clamping line and the bearing line of the wound lap on the rear lap roller since the web can also have a different structure and length of adherence with respect to its unwinding length.
This can lead to the consequence that during the subsequent piecing process of the lap end to the trailing lap end the overlap of the two lap ends can no longer be controlled precisely. This can lead to an overlap of the two lap ends during the piecing process which is too large in one case and too small in another case.
The invention thus has the object of providing a method and an apparatus by which a precise position of the lap severance with respect to the longitudinal direction of the web is enabled.

A method is thus propsed in when the web is clampled over its width and the free end projecting over the clamping position is severed directly after the clamping position by means of a compressed air flow which is produced over the width of the web.
It is further proposed that end of the web severed by the compressed air stream is sucked off from the zone of the clamping position by at least one further air stream.
With this device one obtains a precise position of the severing line of the lap end downstream of the clamping position. The actual severing thus no longer occurs by the reversing movement of the lap rollers, but only by the applied compressed air stream. The clamping device is opened again prior to the reversing of the lap rollers in order to place the prepared lap end on the wound lap again.
Preferably, the compressed air is blown on to the lap end in the immediate vicinity of the clamping position of the web and transversally or under an angle to the longitudinal direction of the clamped web.
The invention is also achieved by an apparatus, with a clamping apparatus and a compressed air nozzle being used which extend over the width of the web, with the compressed air nozzle being arranged adjacently to and on the outlet side of the clamping apparatus and its outlet opening facing the lap end projecting from the clamping apparatus. In order to be able to carry off the end of the web which is severed by the compressed air nozzle it is proposed that a suction conduit is arranged on the outlet side of the clamping apparatus.
In order to achieve a compact design and a controlled air stream it is proposed further that the clamping apparatus is fastened on the suction conduit and the compressed air

nozzle projects at least with its opening into the suction duct.
The compressed air nozzle can be arranged in such a way that individual nozzle openings which are arranged adjacent to one another are provided.
Further advantages are shown and described in closer detail by reference of the following embodiment, wherein:
Fig- 1 shows a schematic side view of the web intake of a combing head of a combing machine with the compressed air device in accordance with the invention and
Fig. 2 shows a representation pursuant to fig. 1 with the opened clamping device.
Fig. 1 shows a cross section through the web intake on a combing head 1 of a combing machine in which a wound lap W rests on the driven lap rollers 3, 4. A preparation device 6 for the preparation of the lap end E of the web B is arranged below and between the lap rollers 3 and 4. The preparation device 6 consists of a suction tube 8 and a suction conduit 9 which opens into the tube 8. In the case of eight combing heads there will be eight such conduits 9 which all open into the tube 8. A low-pressure source (not shown in closer detail) is connected to tube 8, as a result of which an air stream is produced from the respective conduit 9 to tube 8, as is indicated with the arrow.
In the upper zone of conduit 8 a wall element 11 is arranged which is swivellable about an axle 10 and which is provided on the inner side with an elastic clamping element 12. The clamping element 12 could be made of rubber, for example. As is shown schematically, the clamping element 12 is pressed against the web B projecting into the conduit 9 and the opposite fixed wall portion 16 by means of a

cylinder 14 which is articulated on conduit 9 by way of axle 15. Thus a nip line K arises which is present over the entire width of web B.
Cylinder 14 is connected with the swiveliable wall element 11 by way of the axle 18 and the bracket 19. Cylinder 14 is supplied with compressed air by way of a valve 20 via lines 21 and 22. Valve 20 is controlled by control unit S which also determines the feed direction of the air which is supplied by the compressed air source 24. For monitoring the position of the clamping element 12 and the axle 18 a sensor 26 is attached which is connected with the control unit S via line 27. For monitoring the position of the lap end E a further sensor 29 is provided in the interior of conduit 9, which sensor is connected with the control unit S by way of line 30. A nozzle 32 is attached directly below the clamping position K whose opening 33 faces the interior of conduit 9. The opening 33 can consist of individual openings which are arranged adjacent to one another and are arranged in a distributed manner over the width of the web. Opening 33 could also be arranged as a narrow slot which extends over the width of the web and is supplied via line 35 with compressed air which is supplied via compressed air source 37. The control of the supply of compressed air is made through valve 36 which is controlled by control element 38 by way of the control unit S. The control unit S is connected with control element 38 through line 39. A removal apparatus 42 is swivellably arranged on axle 5 of the lap roller 3^ which apparatus produces an approximately tangential air stream to wound lap W via a schematically shown nozzle element 4 3 for the removal of the prepared lap end E. A more detailed description of this device is given in EP-Al-4 82 47 5 for example. It also discloses further details concerning the arrangement of the preparation device 6.

Furthermore, a nipper unit Z with a feed roller SW is shown schematically. The web B which is wound off of wound lap W is supplied to the nipper unit Z by way of a pair of press rollers 44.
The drive of the pair of press rollers 44 and of the nipper unit Z is deactivated in the position as shown in figs. 1 and 2. It will only be activated again if a newly prepared lap end E is pieced on the trailing lap end El via the removal apparatus 42. The preparation of the trailing lap end El can occur according to the description of the former European patent application No. 455 171 in which this process is described in closer detail.
In fig. 2 the piston of cylinder 14 is retracted and the clamping element 12 is lifted off from the opposite wall 16 of conduit 9. This means that the wall element 11 was swivelled through axle 10 counterclockwise by the retraction of the cylinder 14. Conduit 9 is thus open again for receiving and sucking in a new lap end E.
The preparation process for the lap end E is described in closer detail below by reference to figs. 1 and 2:
After the lap end El of the trailing web B was prepared, as is described in EP-Al-455 171, and is situated in the shown position in fig. 2, a new wound lap W is placed on the lap rollers 3 and 4. Wound lap W is rotated in the direction of arrow PI by the driven lap rollers 3, 4 and a pressure below atmospheric is applied to suction tube 8 and to conduit 9, so that an air stream arises in conduit 9, as is indicated by the arrows. As soon as the end E of the outer web B which rests on wound lap W is grasped by the suction of conduit 9, the same is now lifted off from the outer periphery of the wound lap by further rotation of wound lap W and pulled into the conduit 9. Once the sensor 29 has recognised the end E the drive of lap rollers 3 and 4 and

thus the rotation of wound lap W is stopped. This is initiated by the control unit S which receives the signal of sensor 29 via path 30. The control unit S now switches valve 20 to the respective position, as a result of which piston of cylinder 14 is charged on one side with compressed air through line 22. As a result, the piston of cylinder 14 extends and wall 11 with the clamping element 12 swivels clockwise about axle 10. This swivelling movement is monitored via sensor 26 which on reaching the end position stops the further supply of cylinder 14 with compressed air. In this end position the clamping element 12 rests on web B and presses the same against the fixed wall 16, as is shown in fig. 1. On reaching this clamped position, valve 36 is actuated via the control unit S, as a result of which the compressed air produced by compressed air source 37 reaches opening 33 of nozzle 32. The compressed air pulse is set in such a way that the lap end E is severed immediately behind the clamping position K in a defined manner. This means that the severing line is located precisely on the line of openings 33. The thus severed lap end E is sucked downwardly and is discharged. As soon as this severing process has occurred, valve 20 is again triggered via the control unit S and cylinder 14 is supplied with compressed air through line 21. In this way the piston rod of cylinder 14 is retracted and the wall element is swivelled back to the position as shown in fig. 2.
Shortly after the clamping via the clamping element has been lifted, the lap rollers 3 and 4 are driven in the direction as shown in fig. 1, as a result of which the wound lap rotates in the direction of arrow P2 (fig. 1) . This direction of rotation is retained until the new and prepared lap end E reaches the zone of the bearing point between lap roller 4 and wound lap W in order to place it on the outer periphery of wound lap W. As soon as the lap end E which was severed through nozzle 32 was sucked off by

the suction device (9, 8) , the suction air stream is switched off again.
Then the lap rollers are reversed again and the wound lap is rotated in the direction of arrow PI, so that the new lap end E which is placed on the outer periphery reaches the zone of the removal apparatus 42 through which it is taken off and transferred to the press rollers 44 and the trailing lap end El. The piecing of the new lap end E on the trailing lap end El is controlled and co-ordinated time-wise in such a way that in the zone of the press rollers 44 there will be a piecing location without any thin or thick places. Now the normal unwinding process of the web B from the wound lap W can occur in order to perform the combing process in nipper unit Z in conjunction with the circular comb (not shown).
As a result of this proposed preparation of the lap end, a precisely defined severing location is achieved, as a result of which the subsequent overlapping process with the trailing lap end El and the newly prepared lap end E can be performed precisely-


WE CLAIM
1. A method for preparing a lap end (E) of a web (B) for subsequent further processing of the web, characterized in that the web (B) is clamped over its width and the free end (E) projecting over the clamping position (K) is severed directly after the clamping position by means of a compressed air flow which is produced approximately over the width of the web.
2. A method as claimed in claim 1, characterized in that the end (E) of the web (B) severed by the compressed air stream is sucked off from the zone of the clamping position (K) by at least one further air stream.
3. A method as claimed in one of the claims 1 to 2, characterized in that in the immediate vicinity of the clamping position (K) of. the web (B) the compressed air is blown on to the lap end (E) trans vers ally or under an angle to the longitudinal direction of the clamped web (B).
4. An apparatus for preparing a lap end (E) of a web (B) for a subsequent further processing of the web, characterized by a clamping apparatus (11, 12, 14, 16) and a compressed air nozzle (32) which extend over the width of the web (B) , with the compressed air nozzle being arranged adjacently to and on the outlet side of the clamping apparatus and its outlet opening (33) facing the lap end (E) projecting from the clamping apparatus.
5. An apparatus as claimed in claim 4, characterized in that a suction conduit (9) is arranged on the outlet side of the clamping apparatus (11, 12, 14, 16).

6. An apparatus as claimed in claim 5, characterized in
that the clamping apparatus (11, 12, 14, 16) is
fastened on the suction conduit (9) and the compressed
air nozzle (32) projects into the suction conduit at
least with its opening (33) .
7. An apparatus as claimed in claim 6, characterized in
that the compressed air nozzle (32) is provided with
nozzle apertures (33) which are arranged individually
adj acent to one another.
8. A method for preparing a lap end substantially as herein
described with reference to the accompanying drawings
9. An apparatus for preparing a lap end substantially as herein
described with reference to the accompanying drawings.
Dated this 21st day of September 1998


Documents:

2113-mas-1998-abstract.pdf

2113-mas-1998-assignment.pdf

2113-mas-1998-claims duplicate.pdf

2113-mas-1998-claims original.pdf

2113-mas-1998-correspondance others.pdf

2113-mas-1998-correspondance po.pdf

2113-mas-1998-description complete duplicate.pdf

2113-mas-1998-description complete original.pdf

2113-mas-1998-drawings.pdf

2113-mas-1998-form 1.pdf

2113-mas-1998-form 26.pdf

2113-mas-1998-form 3.pdf

2113-mas-1998-other documents.pdf

abs-2113-mas-1998.jpg


Patent Number 204474
Indian Patent Application Number 2113/MAS/1998
PG Journal Number 26/2007
Publication Date 29-Jun-2007
Grant Date 22-Feb-2007
Date of Filing 21-Sep-1998
Name of Patentee MASCHINENFABRIK RIETER AG
Applicant Address Klosterstrasse 20, CH-8406, Winterthur
Inventors:
# Inventor's Name Inventor's Address
1 LEUZINGER ALBIN 800 MUD CREEK ROAD IN MAIN, S.C. 29349,
PCT International Classification Number B65H67/08
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 197 42 300.0 1997-09-22 Germany