Title of Invention	A METHOD OF WINDING A LAP SHEET ONTO A TUBE OF A LAP-FORMING MACHINE AND AN APPARATUS FOR PRODUCING LAPS ON A LAP-FORMING MACHINE
Abstract	The present invention concerns a method of winding a lap sheet onto a tube on a lap-forming machine, and an apparatus for producing laps. In known devices towards the end of the lap winding process the lap width (8) is reduced in such a manner that the tailing lap sheet end wound onto the complet- ed lap roller (5) presents lap sheet edges shifted inwards. As in these devices the lap sheet tearing line (AR) of the lap sheet (6) and the position of the point where the lap sheet width has been brought back to the original width (8) do not coincide, the first lap sheet layers wound onto a new empty tube in a new lap winding process are of the narrowed lap sheet width (81). The disadvantages caused by such initial layers of narrowed width are eliminated in that at a time moment before the lap winding process ends the lap sheet (6) supplied to the tube (7) is narrowed in its width (81) during a determined time interval (I-II) and subsequently is brought back to its original lap sheet width (8).

Title of Invention

A METHOD OF WINDING A LAP SHEET ONTO A TUBE OF A LAP-FORMING MACHINE AND AN APPARATUS FOR PRODUCING LAPS ON A LAP-FORMING MACHINE

Abstract

The present invention concerns a method of winding a lap sheet onto a tube on a lap-forming machine, and an apparatus for producing laps. In known devices towards the end of the lap winding process the lap width (8) is reduced in such a manner that the tailing lap sheet end wound onto the complet- ed lap roller (5) presents lap sheet edges shifted inwards. As in these devices the lap sheet tearing line (AR) of the lap sheet (6) and the position of the point where the lap sheet width has been brought back to the original width (8) do not coincide, the first lap sheet layers wound onto a new empty tube in a new lap winding process are of the narrowed lap sheet width (81). The disadvantages caused by such initial layers of narrowed width are eliminated in that at a time moment before the lap winding process ends the lap sheet (6) supplied to the tube (7) is narrowed in its width (81) during a determined time interval (I-II) and subsequently is brought back to its original lap sheet width (8).

Full Text	Control of the Lap Build-up The present invention concerns a method of winding a lap sheet onto a tube of lap-forming machine and an apparatus for implementing the method. In machines for building up a lap roller it is known, as described e.g. in the DE-OS 1685609, that towards the end of the lap winding process the lap sheet fed to the lap winding aggregate is narrowed by adjusting the position of lateral lap sheet guides. As the lap sheet is narrowed in its width a slight compression is generated in the area of the lap sheet edges in such a manner that the edge fibres are better integrated into the lap sheet. Thus a more compact lap sheet end is obtained which is joined more easily to a tailing lap sheet end running out in a combing machine. This presents an advantage especially if on the subsequent combing machine the leading lap sheet end of a new lap is joined in fully automatically and is taken off using an automatic take-off device. On newer ribbon tappers, see e.g. on the SR80 by Marzoli (imprint Stampa GRA-PHOS-BG-Printed in ltaly-66613120SR80 3/M), upstream of the winding aggregate proper (winding rolls) a number of calender rolls is arranged in order to prepare the lap sheet for the winding process. Upstream of the calender rolls in this arrangement also a device is arranged using which the lap sheet can be narrowed in its width shortly before the winding process ends. This narrowing of the lap sheet in its width in this arrangement is released only when after ejection of the completed lap the winding process is re-started for building up a new lap. In this procedure the lap-forming machine is stopped as soon as an appropriate device signals that a predetermined number of meters of lap sheet has been wound onto the tube. During this stopping action the lap sheet guide arranged upstream of the calender rolls still is pivoted in, in which position narrowing of the lap sheet width is effected. The tearing line at which the lap sheet is torn off before the completed lap is ejected is located in the area between the front calender roll and the back winding roll. This means that the lap sheet end present between the lap sheet guide and the calender rolls and up to the tearing line is narrowed in its width. Thus in the subsequent lap winding process at least the first layers wound onto a newly inserted empty tube are narrowed in their width. The lap sheet guide being re-opened as the lap winding operation is started anew the subsequent lap layers present a larger lap sheet width. Due to this shift of the lap sheet edges in at least two layers on the tube disturbances in the unrolling process on the subsequent combing machine may occur, particularly if short fibres are processed. This signifies that in the area of the lap sheet edges shifted inward on the tube felting may occur with the superimposed layers as well as shifting between fibres in such a manner that, as the outer lap sheet layers are unrolled, also portions of the inner lap sheet layer the edges of which are shifted inward are peeled off prematurely. Due to these disturbances the lap sheet fed to the combing machine is rendered uneven and partially presents thick places. Furthermore the unrolling process monitored by a sensor no longer can be controlled exactly while the lap on the tube is running out. This signifies that holes in the lap sheet which might occur possibly are not caught by the sensor if they pass too far from the sensor which is arranged fixedly. It thus is the goal of the present invention to avoid the disadvantages described. This goal is achieved on one hand using the method according to claim 1. The time co-ordination, proposed in this method, of the narrowing of the lap Sheet in its width and of the subsequent restoration to the original tap sheet width which follows after a time delay permits that at the re-start of a new lap winding process a lap sheet of constant and original width can be wound onto the empty new tube. This signifies that owing to the precisely timed re-opening of the lap guide, co-ordinated to the geometrical conditions, close coincidence of the point in the lap sheet where the original width is restored with the lap sheet tearing line can be achieved. Preferentially the time moment, and the time interval respectively, for narrowing the lap sheet width, and for re-setting the lap sheet guide to its original position respectively, Proposed by means of monitoring the lap sheet length wound up. The goal of the present invention on the other hand also is achieved owing to the characteristics of the apparatus described in the characterizing part of claim 3, claiming that the adjusting device of the lap sheet guide be associated with a control unit which is equipped with a corresponding control programme and which causes, based on the number of meters of lap sheet wound up, an adjustment of the lap sheet guide for narrowing the lap sheet width, and which upon having scanned a further number of meters causes re-setting of the lap sheet guide to its originalposition, in such a manner that upon completion of the lap winding process the lap sheet tearing line generated and the point along the lap sheet at which the lap sheet width is widened back to the original width coincide closely. Further characteristics and advantages of the present invention are described in more detail in the following with reference to an illustrated design example. It is shown in: Fig. 1 a schematic side view of a lap winding apparatus. Fig. 2 an enlarged view seen in the direction of arrow X according to the Fig. 1, Fig. 3 a diagram showing the lap sheet widths wound up, Fig. 4 a schematic diagram of the lap winding process/activation of the lap sheet narrowing adjustment. Fig. 5 a top view of a completed lap. In the Fig. 1 part of a ribbon lap winder is shown in the area of the winding ag- gregate 1 which is provided with two winding rolls 2, 3. on which a lap 5 is built up. The lap 5 is generated by winding a lap sheet 6 onto a tube 7. During the lap winding process the winding rolls are driven by a gear arrangement 50 which is associated with a motor 51. The driving connection between the winding rolls 2, 3 and the gear arrangement 50 here is indicated schematically merely. The winding rolls 2, 3 rotate in directions indicated by the respective arrows. Using a pressing device, not shown in more detail here, which acts in the area of the tube 7, the lap is pressed against the surfaces of the two winding rolls 2, 3 in a controlled manner. Upstream of the back winding roll calender rolls 10, 11, 12 and 13 are rotatably arranged around which the lap sheet is guided in preparation of the lap winding process. The calender rolls 10 through 13 are driven also via the gear arrangement 50, the drive connection 53 to the gear arrangement 50 being indicated schematically. In the driving connection 53 additionally a clutch 54 is built in which is activated via the control device 44. Between the front calender roll 13 and the lap take-up on the winding rolls 2 and 3 a pivotable clamping element 15 is arranged which for the tearing of the lap sheet generates a clamping line on the winding roll 2. The clamping element 15 is pivoted by a correspondingly co-ordinated cylinder 56 controlled by a valve 57.Control of the valve 57 is effected by the control device 44 which via the circuit 58 is connected to the valve 57. On the axle of the calender roll 13 a sensor element is arranged which scans the rotatory motion of the calender roll 13. The sensor 60 is connected to the control device 44 via a circuit 61. The rotation impulses transmitted are processed in the control device under consideration of the radius of the calender roll 13 and yield a conclusion concerning the lap sheet length transported on the calender roll 13. Upstream of the calender roll 10, seen in the direction T of lap sheet transport, pivotable guide elements 18 and 19 are arranged. As can be seen particularly from the Fig. 2, the guide elements 18 and 19 are linked pivotable about the axes 24. and 25 respectively, to pivoting arms 21, and 22, respectively. Lever arms 27, and 28 respectively, are non-rotatably connected to the pivoting arms 21, and 22 respectively, and their respective ends are taken up in a common linking pin 30. A cylinder 31 acts onto the linking pin 30 the position of which is adjusted by the cylinder 31. The cylinder is fed via a valve 32 which in turn is controlled by the control device 44. Owing to the linking mentioned with the pivoting arms 21 and 22 a movement of the cylinder 31 also effects a lateral movement of the guide elements 18 and 19. For offsetting the variable length of the lever arms 27 and 28 in relation to the fixed position of the pivoting axes are provided with slot-like holes in the area of the linking point of the linking pin. Upstream of the guide elements 18 and 19 further guide elements 34 and 35 are provided which also serve for laterally guiding the lap sheet fed and are mounted fixedly. Using the cylinder 31, as described already, adjustment of the guide elements 18 and 19 can be effected in such a manner that the original lap sheet width B is narrowed to a lap sheet width B1. In the Fig. 3 a schematic diagram is given of the changes in width of the lap sheet in the course of the lap winding process As soon as the sensor 60 transmits a signal to the control device 44 indicating that of the desired total lap sheet length of 350 m only 3 more meters are to be wound up the valve 32 is activated by the control device 44 in such a manner t hat the cylinder 31 is pressurized and effects the adjustment of the lap sheet guide elements 18 and 19. Thus the lap sheet width is reduced from 300 mm to 280 mm. In the Fig. 3 also the diagram of the lap sheet widths wound onto the lap 5 is shown. In the Fig. 4 on one hand in a curve C the width of the lap sheet wound up is plotted over a lap winding cycle W and on the other hand in a curve D the switching cycle, or the adjustments respectively, of the lap sheet guides 18, 19 are plotted in relation to the curve C. The switching cycle is understood as describing the moment in time in which the lap sheet guide elements are moved inward in such a manner that the lap sheet width B is narrowed to the lap sheet width B1. From the Fig, 4 the time moment I indicates that 347 m of lap sheet have been wound up. This is scanned by the sensor 60 as described already. At the time moment I the lap sheet guide elements 18, 19 are are moved inward in such a manner that from this moment on a smaller lap sheet of the width B1 is supplied from the lap sheet guide elements 18, 19 to the subsequent calender rolls 10 through 13. Un- in the hallowed rap sheet mainly is wound onto the tap 5 ar the point p5 it must over the distance E which corresponds to the distance between the points P2 and P5. Thus the time moment in which the lap sheet narrows on the curve C and the time moment of the inward movement of the lap sheet guide elements do not coincide. At the time moment II the lap sheet guide elements 18, 19 are set back again in such a manner that the lap sheet width again is brought back to the original lap sheet width B. The time moment II is chosen in such a manner that until the lap winding cycle ends the lap of the width B again fed to the winding aggregate 1 still covers a distance G which corresponds to the transporting distance of the lap sheet between the point P2 and the lap sheet tearing line AR. The distance G could, depending on the lay-out considered, also represent the distance between the points P2 and P3. It thus is ensured that the lap sheet which now is widened again no longer reaches the almost completed lap 5. This is shown especially in the Fig. 5 in which a completed lap is shown which already has been ejected. The end 62 of the lap sheet is deposited at a defined point on the lap 5 and the edges 63 and 64 of this outermost lap layer are shifted inwards each by the offsetting amount X. In the following the course of the method is summed up again briefly. The course of the method is described from the time moment in which an already completed lap has been ejected towards the front side using an ejecting device 66 shown schematically. The end of the lap sheet then is located at the height of the lap sheet tearing line AR of the lap sheet 6 newly supplied to the winding aggregate 1. The clamping element 15 is located again in its position lifted off the winding roll 2. After an empty new tube has been inserted using an inserting device (not shown) above the winding rolls 2 and 3 the drive of the lap-forming machine is started again. The webs each delivered by a drafting system not shown in more detail here are doubled and superimposed into a lap sheet 6. The drafting systems mentioned as well as further drive elements of the feed table 4 are driven via the drive train 68 by the gear arrangement 50. As the lap winding process is started the leading lap sheet end is transported from the point AR into the take-up area of the newly inserted empty tube 7 and under the influence of a vacuum applied inside the tube and acting via the perforated wall of the tube is taken up along the circumference of the tube and is wound up as the rotation of the tube continues. The lap sheet 6 supplied upon leaving the feed plate is transferred onto a guide plate 37 provided with the lateral guides 34 and 35 and on into the area of the adjustable guide elements 18 and 19. From there the lap sheet is transferred to the calender rolls 10 through 13 around which the lap sheet passes and then is transferred to the back winding roll 2, In the area of the calender rolls 10 through 13 the lap sheet embraces each calender roll over a part of its circumference. The sensor 13 arranged on the front calender roll 13 monitoring the rotatory impulses indirectly scans the lap sheet length delivered and transmits the signals to the control device 44. Shortly before the winding process ends, i.e. shortly before the lap has reached its final size (about 3 more meters of lap sheet length to be wound up) the control device 44 associated with the sensor 60 transmits a control signal to the valve 32 which activates the cylinder 31, Thus the guide elements 18 and 19 in turn are moved inward ant thus the lap sheet width is narrowed from B to B1. Up to the time moment in which the narrowed lap sheet width 81 reaches the lap 5 it covers the distance from point P2 to the point P5. At the time moment 11 (Fig. 4) via the control device 44 the valve 32 again is influenced in such a manner that via the cylinder 31 the guide elements 18 and 19 are moved back. Accordingly the lap sheet width is brought back again to the original width B. As soon as the leading end of the lap sheet now again widened to the width B has reached the lap sheet tearing line the lap-forming machine is stopped using the control device 44. This timing sequence is controlled using also the sensor 60 and the control device 44. Simultaneously with the stopping action the control device 44 via the circuit 55 causes the clutch 54 to be opened. A further clutch 70 is built into the drive train 68 driving the drive elements of the feed table 4 also, which clutch 70 also is opened by the control device via the circuit 71. This signifies that the drive elements of the feed table 4 as well as the drive elements for the calender rolls 10 through 13 are disconnected from the gear arrangement 50. Via the circuit 58 now the valve 57 is influenced in such a manner that the clamping element 15 activated by the cylinder 56 is lowered onto the winding roll 2. After the clamping element has been lowered the drive of the winding rolls 2 and 3 is put into motion at reduced speed in which process, as the calender roll 13 is at a standstill, the leading end of the lap sheet 6 pointing towards the lap 5 is severed between the nip points P3 and P4 in the area of the lap sheet tearing line AR. The drive of the two winding rolls 2 and 3 thereupon is kept in motion until the tailing lap sheet end 62 is deposited at a predetermined point on the outer circumference of the lap 5. Subsequently the drive is stopped and the ejecting device 66 is activated which causes ejection of the completed lap towards the front out of the winding aggregate 1 onto a take-up device (not shown). Detailed description of the release of the device holding the tube 7 during the winding process, well known according to the general state of the art, is dispensed with in the present description. After ejection of the lap 5 a new empty tube 7 is inserted and the clutches 54 and 70 are engaged again via the control device 44. A new lap winding process on the new empty tube 7 thereupon is started. Owing to the stepwise adjustment of the position of the guide elements 18 and 19 the lap sheet portion first to be wound up is of the full width B and thus the disadvantages described initially -the premature pulling out of inner lap sheet layers - are avoided. 1. Method of winding a lap sheet (6) onto a tube (7) of a lap-forming machine characterized in that during a time period before the lap winding process ends the lap sheet (6) supplied to the tube (7) during a determined time interval (Ml) is narrowed in its width (B1) and subsequently is brought back to its original width (B). 2. Method according to claim 1 characterized in that the time moments at which the lap sheet width (B) is narrowed, and at which the lap sheet is brought back to its original width respectively, are determined in function of, and by means of scanning of, the length of the lap sheet (6) wound up. 3. Apparatus for producing laps (5) on a lap-forming machine using the method according to claim 1 with a winding aggregate (1) to which a lap sheet (6) is supplied via calender rolls (10, 11, 12, 13) and with an adjustable lap sheet guide element (18,19) arranged upstream of the calender rolls for influencing the width (B) of the lap sheet supplied to the calender rolls characterized in that the adjusting device (32, 31, 30, 27, 28, 21, 22) of the lap sheet guide element (18, 19) is associated with a control device equipped with a corresponding control programme, which based on the number of meters of the lap sheet (6) wound up as scanned by a sensor device (60) effects an adjustment of the position of the lap sheet guide element (18, 19), which causes narrowing of the lap sheet width (B), and after a determined further number of meters have been scanned, effects a movement of the lap sheet guide elements back to their original position in such a manner that the lap sheet tearing point (AR) generated upon termination of the lap winding process and the point along the lap sheet, at which the lap sheet width had been restored to the original width, closely coincide h» Method of winding a lap sheet substantially as herein described with reference to the accompanying drawings. 5# Apparatus for producing laps on a lap-forming machine substantially as herein described with reference to the the accompanying drawings* Dated this 20th day of Noveffiber 1996 Summary The present invention concerns a method of winding a lap sheet onto a tube on a lap-forming machine, and an apparatus for producing laps. In known devices towards the end of the lap winding process the lap width (B) is reduced in such a manner that the tailing lap sheet end wound onto the completed lap roller (5) presents lap sheet edges shifted inwards. As in these devices the lap sheet tearing line (AR) of the lap sheet (6) and the position of the point where the lap sheet width has been brought back to the original width (B) do not coincide, the first lap sheet layers wound onto a new empty tube in a new lap winding process are of the narrowed lap sheet width (B1). The disadvantages caused by such initial layers of narrowed width are eliminated in that at a time moment before the lap winding process ends the lap sheet (6) supplied to the tube (7) is narrowed in its width (81) during a determined time interval (l-ll) and subsequently is brought back to its original lap sheet width (B). (Fig. 4)

Full Text

Control of the Lap Build-up
The present invention concerns a method of winding a lap sheet onto a tube of lap-forming machine and an apparatus for implementing the method.
In machines for building up a lap roller it is known, as described e.g. in the DE-OS 1685609, that towards the end of the lap winding process the lap sheet fed to the lap winding aggregate is narrowed by adjusting the position of lateral lap sheet guides.
As the lap sheet is narrowed in its width a slight compression is generated in the area of the lap sheet edges in such a manner that the edge fibres are better integrated into the lap sheet. Thus a more compact lap sheet end is obtained which is joined more easily to a tailing lap sheet end running out in a combing machine. This presents an advantage especially if on the subsequent combing machine the leading lap sheet end of a new lap is joined in fully automatically and is taken off using an automatic take-off device.
On newer ribbon tappers, see e.g. on the SR80 by Marzoli (imprint Stampa GRA-PHOS-BG-Printed in ltaly-66613120SR80 3/M), upstream of the winding aggregate proper (winding rolls) a number of calender rolls is arranged in order to prepare the lap sheet for the winding process.
Upstream of the calender rolls in this arrangement also a device is arranged using which the lap sheet can be narrowed in its width shortly before the winding process ends.
This narrowing of the lap sheet in its width in this arrangement is released only when after ejection of the completed lap the winding process is re-started for building up a new lap. In this procedure the lap-forming machine is stopped as soon as an appropriate device signals that a predetermined number of meters of lap sheet has been wound onto the tube. During this stopping action the lap sheet guide arranged upstream of the calender rolls still is pivoted in, in which

position narrowing of the lap sheet width is effected. The tearing line at which the lap sheet is torn off before the completed lap is ejected is located in the area between the front calender roll and the back winding roll. This means that the lap sheet end present between the lap sheet guide and the calender rolls and up to the tearing line is narrowed in its width. Thus in the subsequent lap winding process at least the first layers wound onto a newly inserted empty tube are narrowed in their width. The lap sheet guide being re-opened as the lap winding operation is started anew the subsequent lap layers present a larger lap sheet width.
Due to this shift of the lap sheet edges in at least two layers on the tube disturbances in the unrolling process on the subsequent combing machine may occur, particularly if short fibres are processed. This signifies that in the area of the lap sheet edges shifted inward on the tube felting may occur with the superimposed layers as well as shifting between fibres in such a manner that, as the outer lap sheet layers are unrolled, also portions of the inner lap sheet layer the edges of which are shifted inward are peeled off prematurely. Due to these disturbances the lap sheet fed to the combing machine is rendered uneven and partially presents thick places. Furthermore the unrolling process monitored by a sensor no longer can be controlled exactly while the lap on the tube is running out. This signifies that holes in the lap sheet which might occur possibly are not caught by the sensor if they pass too far from the sensor which is arranged fixedly.
It thus is the goal of the present invention to avoid the disadvantages described.
This goal is achieved on one hand using the method according to claim 1. The time co-ordination, proposed in this method, of the narrowing of the lap Sheet in its width and of the subsequent restoration to the original tap sheet width which follows after a time delay permits that at the re-start of a new lap winding process a lap sheet of constant and original width can be wound onto the empty new tube. This signifies that owing to the precisely timed re-opening of the lap guide, co-ordinated to the geometrical conditions, close coincidence of the point in the lap sheet where the original width is restored with the lap sheet tearing line can be achieved.

Preferentially the time moment, and the time interval respectively, for narrowing the lap sheet width, and for re-setting the lap sheet guide to its original position respectively, Proposed by means of monitoring the lap sheet length wound up.
The goal of the present invention on the other hand also is achieved owing to the characteristics of the apparatus described in the characterizing part of claim 3, claiming that the adjusting device of the lap sheet guide be associated with a control unit which is equipped with a corresponding control programme and which causes, based on the number of meters of lap sheet wound up, an adjustment of the lap sheet guide for narrowing the lap sheet width, and which upon having scanned a further number of meters causes re-setting of the lap sheet guide to its originalposition, in such a manner that upon completion of the lap winding process the lap sheet tearing line generated and the point along the lap sheet at which the lap sheet width is widened back to the original width coincide closely.
Further characteristics and advantages of the present invention are described in more detail in the following with reference to an illustrated design example. It is shown in:
Fig. 1 a schematic side view of a lap winding apparatus.
Fig. 2 an enlarged view seen in the direction of arrow X according to the Fig. 1,
Fig. 3 a diagram showing the lap sheet widths wound up,
Fig. 4 a schematic diagram of the lap winding process/activation of the lap sheet narrowing adjustment.
Fig. 5 a top view of a completed lap.
In the Fig. 1 part of a ribbon lap winder is shown in the area of the winding ag-

gregate 1 which is provided with two winding rolls 2, 3. on which a lap 5 is built up. The lap 5 is generated by winding a lap sheet 6 onto a tube 7. During the lap winding process the winding rolls are driven by a gear arrangement 50 which is associated with a motor 51. The driving connection between the winding rolls 2, 3 and the gear arrangement 50 here is indicated schematically merely. The winding rolls 2, 3 rotate in directions indicated by the respective arrows. Using a pressing device, not shown in more detail here, which acts in the area of the tube 7, the lap is pressed against the surfaces of the two winding rolls 2, 3 in a controlled manner. Upstream of the back winding roll calender rolls 10, 11, 12 and 13 are rotatably arranged around which the lap sheet is guided in preparation of the lap winding process. The calender rolls 10 through 13 are driven also via the gear arrangement 50, the drive connection 53 to the gear arrangement 50 being indicated schematically. In the driving connection 53 additionally a clutch 54 is built in which is activated via the control device 44.
Between the front calender roll 13 and the lap take-up on the winding rolls 2 and 3 a pivotable clamping element 15 is arranged which for the tearing of the lap sheet generates a clamping line on the winding roll 2. The clamping element 15 is pivoted by a correspondingly co-ordinated cylinder 56 controlled by a valve 57.Control of the valve 57 is effected by the control device 44 which via the circuit 58 is connected to the valve 57. On the axle of the calender roll 13 a sensor element is arranged which scans the rotatory motion of the calender roll 13. The sensor 60 is connected to the control device 44 via a circuit 61. The rotation impulses transmitted are processed in the control device under consideration of the radius of the calender roll 13 and yield a conclusion concerning the lap sheet length transported on the calender roll 13.
Upstream of the calender roll 10, seen in the direction T of lap sheet transport, pivotable guide elements 18 and 19 are arranged. As can be seen particularly from the Fig. 2, the guide elements 18 and 19 are linked pivotable about the axes 24. and 25 respectively, to pivoting arms 21, and 22, respectively. Lever arms 27, and 28 respectively, are non-rotatably connected to the pivoting arms 21, and 22 respectively, and their respective ends are taken up in a common linking pin 30.

A cylinder 31 acts onto the linking pin 30 the position of which is adjusted by the cylinder 31. The cylinder is fed via a valve 32 which in turn is controlled by the control device 44. Owing to the linking mentioned with the pivoting arms 21 and 22 a movement of the cylinder 31 also effects a lateral movement of the guide elements 18 and 19. For offsetting the variable length of the lever arms 27 and 28 in relation to the fixed position of the pivoting axes are provided with slot-like holes in the area of the linking point of the linking pin. Upstream of the guide elements 18 and 19 further guide elements 34 and 35 are provided which also serve for laterally guiding the lap sheet fed and are mounted fixedly. Using the cylinder 31, as described already, adjustment of the guide elements 18 and 19 can be effected in such a manner that the original lap sheet width B is narrowed to a lap sheet width B1.
In the Fig. 3 a schematic diagram is given of the changes in width of the lap sheet in the course of the lap winding process As soon as the sensor 60 transmits a signal to the control device 44 indicating that of the desired total lap sheet length of 350 m only 3 more meters are to be wound up the valve 32 is activated by the control device 44 in such a manner t hat the cylinder 31 is pressurized and effects the adjustment of the lap sheet guide elements 18 and 19. Thus the lap sheet width is reduced from 300 mm to 280 mm. In the Fig. 3 also the diagram of the lap sheet widths wound onto the lap 5 is shown.
In the Fig. 4 on one hand in a curve C the width of the lap sheet wound up is plotted over a lap winding cycle W and on the other hand in a curve D the switching cycle, or the adjustments respectively, of the lap sheet guides 18, 19 are plotted in relation to the curve C. The switching cycle is understood as describing the moment in time in which the lap sheet guide elements are moved inward in such a manner that the lap sheet width B is narrowed to the lap sheet width B1. From the Fig, 4 the time moment I indicates that 347 m of lap sheet have been wound up. This is scanned by the sensor 60 as described already. At the time moment I the lap sheet guide elements 18, 19 are are moved inward in such a manner that from this moment on a smaller lap sheet of the width B1 is supplied from the lap sheet guide elements 18, 19 to the subsequent calender rolls 10 through 13. Un-

in the hallowed rap sheet mainly is wound onto the tap 5 ar the point p5 it must
over the distance E which corresponds to the distance between the points P2 and P5. Thus the time moment in which the lap sheet narrows on the curve C and the time moment of the inward movement of the lap sheet guide elements do not coincide. At the time moment II the lap sheet guide elements 18, 19 are set back again in such a manner that the lap sheet width again is brought back to the original lap sheet width B. The time moment II is chosen in such a manner that until the lap winding cycle ends the lap of the width B again fed to the winding aggregate 1 still covers a distance G which corresponds to the transporting distance of the lap sheet between the point P2 and the lap sheet tearing line AR. The distance G could, depending on the lay-out considered, also represent the distance between the points P2 and P3. It thus is ensured that the lap sheet which now is widened again no longer reaches the almost completed lap 5. This is shown especially in the Fig. 5 in which a completed lap is shown which already has been ejected. The end 62 of the lap sheet is deposited at a defined point on the lap 5 and the edges 63 and 64 of this outermost lap layer are shifted inwards each by the offsetting amount X.
In the following the course of the method is summed up again briefly.
The course of the method is described from the time moment in which an already completed lap has been ejected towards the front side using an ejecting device 66 shown schematically. The end of the lap sheet then is located at the height of the lap sheet tearing line AR of the lap sheet 6 newly supplied to the winding aggregate 1. The clamping element 15 is located again in its position lifted off the winding roll 2.
After an empty new tube has been inserted using an inserting device (not shown) above the winding rolls 2 and 3 the drive of the lap-forming machine is started again. The webs each delivered by a drafting system not shown in more detail here are doubled and superimposed into a lap sheet 6. The drafting systems mentioned as well as further drive elements of the feed table 4 are driven via the drive train 68 by the gear arrangement 50. As the lap winding process is started

the leading lap sheet end is transported from the point AR into the take-up area of the newly inserted empty tube 7 and under the influence of a vacuum applied inside the tube and acting via the perforated wall of the tube is taken up along the circumference of the tube and is wound up as the rotation of the tube continues. The lap sheet 6 supplied upon leaving the feed plate is transferred onto a guide plate 37 provided with the lateral guides 34 and 35 and on into the area of the adjustable guide elements 18 and 19. From there the lap sheet is transferred to the calender rolls 10 through 13 around which the lap sheet passes and then is transferred to the back winding roll 2, In the area of the calender rolls 10 through 13 the lap sheet embraces each calender roll over a part of its circumference. The sensor 13 arranged on the front calender roll 13 monitoring the rotatory impulses indirectly scans the lap sheet length delivered and transmits the signals to the control device 44. Shortly before the winding process ends, i.e. shortly before the lap has reached its final size (about 3 more meters of lap sheet length to be wound up) the control device 44 associated with the sensor 60 transmits a control signal to the valve 32 which activates the cylinder 31, Thus the guide elements 18 and 19 in turn are moved inward ant thus the lap sheet width is narrowed from B to B1. Up to the time moment in which the narrowed lap sheet width 81 reaches the lap 5 it covers the distance from point P2 to the point P5. At the time moment 11 (Fig. 4) via the control device 44 the valve 32 again is influenced in such a manner that via the cylinder 31 the guide elements 18 and 19 are moved back. Accordingly the lap sheet width is brought back again to the original width B. As soon as the leading end of the lap sheet now again widened to the width B has reached the lap sheet tearing line the lap-forming machine is stopped using the control device 44. This timing sequence is controlled using also the sensor 60 and the control device 44. Simultaneously with the stopping action the control device 44 via the circuit 55 causes the clutch 54 to be opened. A further clutch 70 is built into the drive train 68 driving the drive elements of the feed table 4 also, which clutch 70 also is opened by the control device via the circuit 71. This signifies that the drive elements of the feed table 4 as well as the drive elements for the calender rolls 10 through 13 are disconnected from the gear arrangement 50. Via the circuit 58 now the valve 57 is influenced in such a manner that the clamping element 15 activated by the cylinder 56 is lowered onto the winding roll

2. After the clamping element has been lowered the drive of the winding rolls 2 and 3 is put into motion at reduced speed in which process, as the calender roll 13 is at a standstill, the leading end of the lap sheet 6 pointing towards the lap 5 is severed between the nip points P3 and P4 in the area of the lap sheet tearing line AR. The drive of the two winding rolls 2 and 3 thereupon is kept in motion until the tailing lap sheet end 62 is deposited at a predetermined point on the outer circumference of the lap 5. Subsequently the drive is stopped and the ejecting device 66 is activated which causes ejection of the completed lap towards the front out of the winding aggregate 1 onto a take-up device (not shown). Detailed description of the release of the device holding the tube 7 during the winding process, well known according to the general state of the art, is dispensed with in the present description.
After ejection of the lap 5 a new empty tube 7 is inserted and the clutches 54 and 70 are engaged again via the control device 44. A new lap winding process on the new empty tube 7 thereupon is started. Owing to the stepwise adjustment of the position of the guide elements 18 and 19 the lap sheet portion first to be wound up is of the full width B and thus the disadvantages described initially -the premature pulling out of inner lap sheet layers - are avoided.

1. Method of winding a lap sheet (6) onto a tube (7) of a lap-forming machine
characterized in that
during a time period before the lap winding process ends the lap sheet (6) supplied to the tube (7) during a determined time interval (Ml) is narrowed in its width (B1) and subsequently is brought back to its original width (B).
2. Method according to claim 1
characterized in that
the time moments at which the lap sheet width (B) is narrowed, and at which the lap sheet is brought back to its original width respectively, are determined in function of, and by means of scanning of, the length of the lap sheet (6) wound up.
3. Apparatus for producing laps (5) on a lap-forming machine using the method
according to claim 1 with a winding aggregate (1) to which a lap sheet (6) is
supplied via calender rolls (10, 11, 12, 13) and with an adjustable lap sheet
guide element (18,19) arranged upstream of the calender rolls for influencing
the width (B) of the lap sheet supplied to the calender rolls
characterized in that
the adjusting device (32, 31, 30, 27, 28, 21, 22) of the lap sheet guide element (18, 19) is associated with a control device equipped with a corresponding control programme, which based on the number of meters of the lap sheet (6) wound up as scanned by a sensor device (60) effects an adjustment of the position of the lap sheet guide element (18, 19), which causes narrowing of the lap sheet width (B), and after a determined further number of meters have been scanned, effects a movement of the lap sheet guide elements back to their original position in such a manner that the lap sheet tearing point (AR) generated upon termination of the lap winding process and the point along the lap sheet, at which the lap sheet width had been restored to the original width, closely coincide

h» Method of winding a lap sheet substantially as herein described with reference to the accompanying drawings.
5# Apparatus for producing laps on a lap-forming machine
substantially as herein described with reference to the the accompanying drawings*
Dated this 20th day of Noveffiber 1996

Summary
The present invention concerns a method of winding a lap sheet onto a tube on a lap-forming machine, and an apparatus for producing laps.
In known devices towards the end of the lap winding process the lap width (B) is reduced in such a manner that the tailing lap sheet end wound onto the completed lap roller (5) presents lap sheet edges shifted inwards. As in these devices the lap sheet tearing line (AR) of the lap sheet (6) and the position of the point where the lap sheet width has been brought back to the original width (B) do not coincide, the first lap sheet layers wound onto a new empty tube in a new lap winding process are of the narrowed lap sheet width (B1). The disadvantages caused by such initial layers of narrowed width are eliminated in that at a time moment before the lap winding process ends the lap sheet (6) supplied to the tube (7) is narrowed in its width (81) during a determined time interval (l-ll) and subsequently is brought back to its original lap sheet width (B).
(Fig. 4)

Documents:

2073-mas-1996-abstract.pdf

2073-mas-1996-claims duplicate.pdf

2073-mas-1996-claims original.pdf

2073-mas-1996-correspondance others.pdf

2073-mas-1996-correspondance po.pdf

2073-mas-1996-description complete duplicate.pdf

2073-mas-1996-description complete original.pdf

2073-mas-1996-drawings.pdf

2073-mas-1996-form 1.pdf

2073-mas-1996-form 26.pdf

2073-mas-1996-form 3.pdf

2073-mas-1996-other documents.pdf

abs-2073-mas-1996.jpg

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Patent Number

207272

Indian Patent Application Number

2073/MAS/1996

PG Journal Number

26/2007

Publication Date

29-Jun-2007

Grant Date

01-Jun-2007

Date of Filing

20-Nov-1996

Name of Patentee

MR. MASCHINENFABRIK RIETER AG

Applicant Address

KLOSTERASSE 20, CH-8406 WINTERTHUR.

Inventors:

#	Inventor's Name	Inventor's Address
1	MASCHINENFABRIK RIETER AG	KLOSTERASSE 20, CH-8406 WINTERTHUR.

PCT International Classification Number

D01G27/00

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	03646/95	1995-12-22	Switzerland