Abstract:
A web is fed into a sheet severer prior to its entry into a subsequent processing stage. The sheets, which have been severed from the web are then cut into required product sections in a cross-cutter which is associated with this subsequent processing stage. In order to achieve an accurately registered severing process, using the sheet severer, it is triggered by a signal which represents the phase position of the cross-cutter. The sheet severer is thus phase-correlated in relation to the phase position of the cross-cutter.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This patent application is the U.S. national phase, under 35 USC 371, of PCT/EP2005/051246, filed Mar. 17, 2005; published as WO 2005/097645 A1 on Oct. 20, 2005 and claiming priority to DE 10 2004 016 674.9, filed Apr. 5, 2004 and to DE 10 2004 053 536.1, filed Nov. 5, 2004, the disclosures of which are expressly incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention is directed to a method and to devices for severing a continuous web and/or for feeding such a continuous into a further processing stage. The continuous web is cut transversely into product sections in a processing stage that is subsequent to an initial severing stage. 
   BACKGROUND OF THE INVENTION 
   DE 195 25 169 C2 discloses a severing device which is arranged in the path of the continuous web, and which severing device is arranged, in the path of the continuous web, upstream of the transverse cutting arrangement consisting of a blade cylinder and a cooperating cutting groove and folding blade cylinder. The transverse cutting device is assigned to the subsequent folding apparatus, and cuts the continuous web into product sections in the course of its operation. 
   A continuous web guidance device between a former and a folding apparatus and having a severing device is known from DE 101 59 937 A1. The severing device severs the continuous web in case of a stoppage of the folding system. The severing device has a blade element with an actuating assembly which is operated by a pressure medium. A clamping device is arranged upstream of the severing device. 
   DE 42 10 190 A1 discloses a severing device with a safety arrangement. A severed continuous web is moved out of the operating path of the continuous web in the course of being severed. 
   DE 102 22 586 A1 discloses an arrangement for treating a web of material. Respective web severing devices are provided on a web travel path both upstream and downstream of a material treatment station. 
   Two severing devices, which are arranged upstream of a folding unit, are disclosed in JP 04-175 165 A. The first severing device cuts through the running web, and a continuous web section, which was deflected by the first cut, is cut off by the second severing device while the machine is stopped. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to providing a dependable method regarding the malfunction-free start of the operation of, and the provision of devices which are suitable for severing and/or for the secure feeding of a continuous web into a further processing stage. 
   In accordance with the present invention, the object is attained by the provision of a method and a device for severing and subsequently transversely cross-cutting and folding a web. The web is initially severed and is then subsequently cross-cut into the plurality of product sections which are then folded. The severing of the web is accomplished, in a registration-correct manner by the severing device. This is triggered in a phase-correlated manner, with respect to the phase relationship of the transverse cutting device, by a signal that represents the phase relationship of the transverse cutting arrangement. 
   The advantages to be gained by the present invention lie, in particular, in that malfunctions, arising because of irregularities in the transverse and/or in the longitudinal extension of the continuous web to be folded, are avoided in the course of feeding a continuous web after severing, or in the course of the first feed-in of a continuous web into a folding apparatus. 
   The start of a continuous web which has been obtained in case of an emergency stop, or also a leading start, which was obtained during the set-up, can, in principle, be oriented in the longitudinal direction in any way with regard to its angular position. In particular, severing of the web can take place at any arbitrary position, with respect to the printed image that is located on the continuous web. The angular position of a transverse blade and of other cylinders of the folding apparatus are brought into longitudinal registration with the printed image, such as, for example, by the electronic or mechanical synchronization of the drive mechanism of the folding apparatus with the angular position of the cylinders applying the printed image, and/or the employment of longitudinal registration devices on the continuous web path. After a re-start, the web cut off, by a transverse cutting arrangement, does also take place at a “correct” location, i.e. at a desired location between two printed images. However, since the upstream or prior severing in the severing device took place, for example, in the middle of a printed page, a shortened product section is initially supplied to the folding apparatus. This shortened product section, because of its length, for example, is not grasped by holding devices of the subsequent transverse cutting device and can lead to considerable malfunctions, including another emergency stop. In accordance with the present method, the continuous web is severed registration-correctly. The start of the continuous web, which was obtained after this registration correct severing process is fed to the folding apparatus. By severing of the web by an additional transverse cutting arrangement, which severing is correct in registration, in regard to the web&#39;s longitudinal direction, the malfunction-free feeding of a start of a continuous web, which had been severed during an emergency stop, for example, into the subsequent or downstream, in the direction of web travel, folding apparatus is assured. 
   Correct registration is also problematical, in the course of an initial web draw-in, or in particular following the severing of a continuous web, if the continuous web is of a width exceeding the customary width of a continuous web. This excess width can be caused by a relative displacement of individual layers, in the transverse direction with respect to each other, or also by an asymmetrical longitudinal fold, both of which can be caused, for example, by an emergency stop itself or by a malfunction which triggered the resulting emergency stop. If such a widened continuous web is now fed to the folding apparatus, this can also result in considerable malfunctions there, up to, and including another emergency stop, but at least can result in incorrect product sections. In a method in accordance with the present invention, the start of the continuous web is only fed to the folding apparatus if the width of the continuous web does not exceed the preset “normal” width of the continuous web. As long as the width of the continuous web is not correct, the continuous web or the severed parts of the continuous web are shunted away. Feeding of the start of a continuous web into the folding apparatus, free of malfunctions, which start of a continuous web was, for example, severed as a result of an emergency stop, is assured by monitoring the width of the continuous web, in regard to the web&#39;s transverse direction. 
   An embodiment of the present invention is particularly advantageous in which both above-mentioned measures, registration-correct severing of the web, and monitoring of the width of the continuous web, are applied. 
   A further problem can arise if several continuous webs are to be fed together to a further processing stage, such as a folding apparatus. In order to be able to operate correctly, such a further processing stage requires an adjustment, in accordance with the thickness of the continuous web, to be processed. In a folding apparatus, this adjustment is the case at the height of the folding jaws. If, in the case of two continuous webs, to whose combined thickness the opening size of the folding jaws has been set, only one web is then fed in, it is not possible for the folding jaw to correctly clamp it. Material falling out of the folding jaws can lead to serious malfunctions. To correct this problem, in the case where two continuous webs are fed to the further processing stage, in which they are separated into product sections, in accordance with the present invention, upstream of the transverse cutting arrangement and along the path of the continuous web, at least the first of these continuous webs passes through a severing device which is operated, synchronized with a leading edge of the second continuous web. The leading edge of the second continuous web and the leading edge of the first continuous web, which are produced by the severing device, meet within the same product section in the further processing device. 
   The leading edges preferably both meet at a border of the product section, or both meet spaced apart from a border between two product sections. In the latter case, the first piece cut off the continuous webs and containing the leading edge is shorter than required for the product sections and the cut-off pieces of both continuous webs are not further processed. In the former case, the cut-off pieces each constitute complete product sections and can be further processed, free of errors. 
   If a severing device is utilized in the course of drawing-in a continuous web to be processed, and if that severing device is also intended to be usable later in case of an emergency web stop, it is necessary for the severing device to be returned to a state in which it is ready to sever the continuous web, which is assigned to it, after it has been used during the draw-in. In accordance with the present invention, this is achieved in that two elements of the severing device, which work together for severing the continuous web, have at least two degrees of freedom of movement with respect to each other. In the second degree of such freedom of movement, the two elements can be changed between a closed position, in which a provided movement, in the first degree of freedom, severs the continuous web, and an open position, in which the provided movement, in the first degree of freedom, does not sever the continuous web. If the web has been severed, in the course of drawing-in the continuous web, by the movement of the severing device in the first degree of freedom, the two elements can be brought into the open position, in the second degree of freedom, to perform, in this position, the movement in the first degree of freedom in the opposite direction without interference with the continuous web. The severing device is then again rendered ready for action by a subsequent movement of the two elements into the closed position. 
   Preferably, the first degree of freedom is a rotatory degree of freedom, and in particular is one which contains a coupled movement of both elements in a counterclockwise direction. Because of this, it is possible to employ elements for the severing device which are also used, in the identical form, in a downstream arranged transverse cutting arrangement, and to thereby reduce the multitude of wear spots in a web processing system comprising the severing device and a transverse cutting arrangement, which is arranged in a downstream located further processing stage. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the present invention are represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
       FIG. 1 , a device which is usable for the dependable severing and/or feeding in of a continuous web, in a web-fed printing machine in accordance with the present invention, in 
       FIG. 2   a )- 2   c ), depictions of three different phases, in the course of registration-correct severing of a web, in 
       FIGS. 3   a ) and  3   b ), the monitoring of the width of the continuous web with two different results, in 
       FIG. 4 , a perspective view of a preferred embodiment of the severing device represented in  FIG. 1 , in 
       FIG. 5   a )- 5   d ), a schematic depiction of the process of operation of the severing device shown in  FIG. 4 , and in 
       FIG. 6 , a continuous web processing system for the simultaneous processing of two fed-in continuous webs, in accordance with the present invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring initially to  FIG. 1 , there is schematically depicted a machine for working and/or for processing webs such as, for example, a machine for producing or processing paper, cardboard, packaging, for example by embossing or imprinting, web-shaped material. In particular there is shown a web-fed rotary printing press, in which a repeated processing pattern B, such as, for example, a printed image, is applied to one or to several webs. After a defined recurring length L B , a further processing stage  01  follows, in which the web, or in which a continuous web  02 , showing the repeated processing pattern, is cut into product sections  04  from one or from several such webs, as shown in  FIG. 4 . 
   The further or subsequent processing stage  01 , may be, for example, a folding apparatus  01 , and has at least one transverse cutting arrangement  03 , in which the continuous web  02  is cut into product sections  04  in accordance with the repeated recurring length L B . The transverse cutting arrangement  03  can possibly also be arranged upstream of the folding apparatus  01 . For the cutting to match the recurring length L B , the transverse cutting arrangement  03  and another unit, which is not specifically represented, and which applies the processing pattern, and which may be, for example a printing group, are synchronized in their operating phase. A path length of the web or webs from the unit to the cut location can be additionally adjusted, if desired, to a whole number multiple of the recurring length L B  by use of a longitudinal register device, which is not represented. In the case of driving the unit and the transverse cutting arrangement  03  by a common drive motor, synchronization can be performed via a mechanical coupling. In the case of the unit and the transverse cutting arrangement  03  being preferably driven mechanically independently of each other by drive motors, synchronization can be accomplished electronically via a so-called virtual guide shaft. In this case, the virtual guide shaft is a component of a machine control device  06 , which is represented schematically in  FIG. 1 . By specifications, in regard to the production speed, the control device can purely synthetically generate angular position set point values Φ and can pass them on to all drive mechanisms of units which are to be synchronized, as well as, for example, to a drive mechanism  07 , such as a drive motor  07  which is particularly regulated in respect to its angular position driving the transverse cutting arrangement  03 , or to one or to several drive mechanisms  07  of the folding apparatus  01  containing the transverse cutting arrangement  03 , for example. However, for synchronization, the angular position set point values Φ of the guide shaft, and therefore of all of the remaining drive mechanisms, can also follow the position of the folding apparatus  01 , or of the transverse cutting arrangement  03 , via the guide shaft. The folding apparatus  01  can also be driven by the drive mechanism  07  from another one of its cylinders. In the same way, several drive mechanisms  07 , which are mechanically independent of each other, such as drive motors  07  which are particularly regulated with respect to their angular position, can drive the cylinders of the folding apparatus  01 . 
   A severing device  09 , which is usable for the spontaneous severing of the continuous web  02 , for example because of an emergency stop, is arranged, in the path of the continuous web  02 , between the unit which applies the processing pattern  08  and the transverse cutting arrangement  03 . This severing device  09  is intended to be usable for cutting through the continuous web at a short reaction time upon receipt of an appropriate command and, in an advantageous further development, to guide the now cut web simultaneously out of the continuous web path leading toward the folding apparatus. Basically, any severing device  09  can be provided for this purpose, in which a blade  11  can be moved into the continuous web path, or out of the continuous web path. 
   In the preferred embodiment shown in  FIG. 1 , the severing device  09  has a blade  11 , which is pivotably seated on its shaft  16  and which blade  11  can be moved into the continuous web path, or out of the continuous web path by pivoting of the shaft  16 . Pivoting of the shaft  16 , and therefore of the blade  11 , takes place via a lever  17 , which is hinged eccentrically with respect to the shaft and which is driven by an actuating device  12  that is operated by a pressure medium. In this case, the actuating device  12  is embodied for being charged with a pressure medium by a control device  15 , or an actuating member  15  which is structured, for example, as a valve, as a response to a signal N standing for an emergency stop. This signal N can originate in the machine control system or, for a short running time, can originate directly in sensors detecting an error. In an advantageous further development, the severing device  09  has a guide element  13 , such as, for example, a deflecting tongue  13 , which works together with the blade  11 , and which, in the active state of the blade  11 , blocks the operational path of the continuous web and guides the continuous web  02  out of the path leading to the folding apparatus  01 . The severing device  09  can furthermore have a hoop  14 , which can be pivoted together with the blade  11 . This hoop  14  aids in the guiding of the newly formed start of the continuous web, again in the direction toward the folding apparatus  01 , when the blade  11  is deactivated. 
   If an error occurs in the course of operating the machine, and wherein the continued entering of the continuous web  02 , or of the webs, into the folding apparatus is to be stopped, the machine is stopped, for example, and the continuous web  02  is severed by the severing device  09 . This is indicated in  FIG. 1  by means of the signal N acting on the actuating member  15 . This severing, typically referred to as an “emergency severing”, takes place spontaneously and without consideration of a location, or a cutting line S, provided for cutting in accordance with the normal operation of the web processing apparatus. During the braking of the installation, the continuous web  02  is conducted out laterally of its usual path by the deflector tongue  13 . As is shown in  FIG. 1 , which depicts in an operational state shortly after the first severing process, during such a so-called emergency severing, as a rule the cut which is formed by the blade  11  does not coincide with the planned cut lines between the recurring lengths L B . Instead a remainder R is left over, as may be seen in  FIG. 2   a ) and is typically of a length less than L B  on the continuous web  02  until the start of a following recurring length L B . 
   In the embodiment of the present invention, with the processing machine being provided as a web-fed printing press, one or several webs are first conducted over a former  18 , for example, and in the process are longitudinally folded into the continuous web  02  prior to its passing through a traction group  19 , the severing device  09  and a further traction group  21  at the inlet to the folding apparatus  01 . The web  02  or the group of several webs is further processed in the folding apparatus  01 . 
   The folding apparatus  01  preferably comprises a cylinder  22  which is embodied as a transport cylinder  22 , such as, for example, a gripper cylinder  22  which, in the embodiment represented in  FIG. 1 , is equipped with five respective web leading end holding elements which the evenly distributed in the circumferential direction, for example grippers  23 , and with folding blades  24 . Together with a cylinder  26 , which is embodied as a cutting blade cylinder  26 , which is provided here with two cutting blades  27 , the gripper cylinder  22  constitutes the transverse cutting arrangement  03 , having a cutting gap  28 . In this cutting gap  28 , the continuous web  02 , or the web shaped material comprised of one or of several layers, is separated into individual product sections  04 , hereinafter sections  04  for short of the recurring length L B , such as, for example, printed products  04  of a length each corresponding to a printed page if, for example, further processing follows, for example a further transverse fold. The holding elements  23  can also be embodied as spur strips  23  containing spur needles, and the transport cylinder  22  can be thus configured as a spur cylinder  22 . 
   Following its passage through the cutting gap  28 , a leading edge of the continuous web  02  is picked up by the holding elements  23 , and specifically is picked up on the spur needles, or is clamped, in particular. In a further development, which is only schematically indicated, the holding elements  23  embodied as grippers  23  can be radially movable out of the shell surface in such a way that they lift a trailing end of a leading product section  04  in order to pick up the edge of the continuous web  02 . By this movement, it is possible to receive product sections  04  on the circumference of the transport cylinder  22  without these product sections  04  being spaced apart from each other. The transport cylinder  22  can thus be operated at the speed of the continuous web without precession. 
   The transport cylinder  22  forms a folding gap  29  together with a further cylinder  31 , such as, for example, a folding jaw cylinder  31 . In the course of their passage through the folding gap  29 , the folding blades  24  are extended out of the transport cylinder  22  to insert the product sections  04  along a center line into folding jaws, which are not specifically represented of the folding jaw cylinder  31 . The product sections  04 , which have been transversely folded in this way, are further conveyed on the folding jaw cylinder  31  to a location at which they are transferred to a paddle wheel, which is not specifically represented for being placed on a conveyor belt, or to a second longitudinal folding apparatus. 
   As can be seen in  FIG. 1 , spontaneous severing, by operation of the severing device  09 , takes place, for example in case of an emergency stop as a result of an error such as, for example, a jam in the folding apparatus  01 . As a result of such an emergency severing, the so-called remainder R constitutes the now leading edge of the continuous web  02 . Even in a case wherein, because of its excessive length, a rerouted section of the continuous web is severed a second time, before it is again fed into the folding apparatus, a remainder R is typically left over until the next operational cut, or before the next occurring operational cutting line S. If now, the continuous web  02  containing the remainder R were fed to the folding apparatus  01 , because of the synchronization with the recurring length L B  a cutting of the remainder R takes place as a first operational cut in the transverse cuffing arrangement  03  which initial cut section, because of its shortened length, cannot be picked up by the holding element  23 . If the risk of a further interference in the operation of the processing machine, caused by this initially shortened length cut segment is to be avoided, the remainder R would have to be removed from the folding apparatus  01  in an elaborate manner. 
   To avoid this elaborate process, a position or length controlled severing device  08 , which can be registration-correctly controlled, is arranged, for example in addition to the severing device  09 , in the path of travel of the continuous web  02  and between the unit applying the processing pattern and the transverse cutting arrangement  03 . In the preferred embodiment, which is represented in the drawing figures, the severing device  09 , which performs the spontaneous severing and which is described above, is arranged in the continuous web path next to the severing device  08  which can be controlled to provide a correct registration. However, in a further development of the present invention, the two functions can also be performed by only a single severing device  08 , provided it additionally takes on the shunt function for removing the severed continuous web  02 . Alternatively, a separate shunt is provided for this web-shunting function. 
   Registration-correct severing is here understood to mean the severing of the continuous web  02 , or webs at an operational cutting line S, which is provided for cutting between two successive recurring length L B . Thus, in the course of the entering of the edge of the new start of the continuous web formed in this way, which new web edge start coincides with the operational cutting line S, into the transverse cutting arrangement  03 , this newly formed web leading edge coincides with the blade  27 , which is moved synchronously with the forward movement of the continuous web  02 , in the effective cutting gap  28 . 
   The registration-correct severing device  08  can be embodied, in any appropriate way, as a severing device  08  or as a transverse cutting device  08 , which is structured to transversely sever the continuous web  02 , or the webs, upon receipt of a triggering signal, in response to which, a blade  32  can be moved into the continuous web path or out of the continuous web path. The registration-correct severing device  08  preferably should be configured so that the cut can be performed at least precisely defined and calculated in view of the reaction time, or the location on the passing continuous web, and/or that a clean cut without large fringes, of for example, less than 5 mm can be achieved. 
   In the preferred embodiment of  FIG. 1 , the severing device  08  has the blade  32 , which is pivotably seated on a shaft  33 , with the blade  32  extending perpendicularly, in respect to the longitudinal extension of the continuous web  02 , and substantially parallel with the level of the continuous web. Pivoting of the shaft  33 , and therefore of the blade  32 , takes place, for example, by actuation of a lever  36 , which lever  36  is hinged eccentrically, with respect to the shaft  33 , via an actuating device  34  which is operated by a pressure medium, such as, for example, by a hydraulic or a pneumatic cylinder with a piston and a rod. In an advantageous further development, the blade  32  acts together, via the continuous web  02 , with a counter support  37 , such as, for example, a counter support  37  configured as a counter blade  37  or as a cutting strip  37 , and wherein they form a cutting groove  41  when working together. This counter blade  37  is either seated fixed in place, or as represented in  FIG. 1  is, in an advantageous embodiment, also pivotably arranged on the other side of the continuous web  02 . To this end the counter blade  37  is also arranged on a shaft  38 , which shaft  38  extends parallel with the shaft  33  and which shaft  38  is driven via a positive driving connection  39 , such as, for example, by a gear wheel pair  39  that are connected with the respective shafts  33 ,  38 , and synchronously with the shaft  33 , but in the opposite direction from shaft  33 . When actuating the controlled web severing device actuator  34 , such as, for example, when an actuator rod connected with the lever  36  is extended, the lever  36  is pivoted upward, from its position shown in  FIG. 1  in a counterclockwise direction, and pivots the shaft  33 , which is connected fixed against relative rotation with it, together with the blade  32  into the cutting groove  41 . By operation of the driving connection  39 , the counter blade  37  moves in the opposite direction of the blade  32  until both work together in the area of the connecting line between the shafts  33 ,  38  for severing the continuous web  02 . Depending on the thickness of the continuous web  02 , cutting of the web  02  takes place more or less prior to reaching the connecting line, which thickness dependent cutting should be advantageously taken into consideration when controlling the severing device in regard to the intended cutting line S. 
   The blade  32  is preferably of the same construction as the blades  27  of the blade cylinder  26 , so that the same replacement can be used for both. In the same way, the counter blade  37  or the cutting strip  37  is identical with a corresponding portion of the transport cylinder  22 , which is acting together with the blades  27 . 
   The phase of the actuation of the severing device  08  is correlated with the transverse cutting arrangement  03 . Registration-correct triggering of the severing device  08 , for subsequent operational cutting, or in other words, its triggering at the right moment, with respect to the forward moving continuous web  02 , takes place on the basis of a signal formed in connection with status information I, and in particular, in accordance with phase information I, and which is referred to as signal I, for short, regarding the operational transverse cutting arrangement  03  of the folding apparatus, for example. In connection with a transverse cutting arrangement  03  which is based on rotating blades  27 , this phase information I represents an angle information of the blade cylinder  26  that is driven synchronously with the continuous web  02 . As represented in  FIG. 1 , the phase information I can be advantageously obtained directly at the cutting blade cylinder  26  by the use of an appropriate detection system  42 , such as, for example, a sensor which is working together with an initiator which is connected, fixed against relative rotation, with the blade cylinder  26 . In that case, this initiator has a fixed, exactly selected angular relationship with the controlled web severing device  08  for registration-correct severing, so that severing by the controlled web severing device  08  takes place based on a pulse which is generated during the passage of the initiator past the sensor. 
   By the use of an embodiment, which is not specifically represented, it is possible to pick up the phase information at any arbitrary other component which is driven synchronously and phase-correlated in respect to the web, or continuous web  02 . However, this only applies to components located upstream or downstream of the controlled web severing device  08 , on whose continuous web path up to the transverse cutting arrangement  03  and up to the severing device  08  no longitudinal registration device is arranged, which longitudinal registration device would possibly change the path length. If this were the case, it would be necessary to provide a correction which would take the change in web path length into consideration as an offset. 
   In a representation which is shown in dashed lines in  FIG. 1 , the phase information I can also be derived from the master shaft of the machine control device  06 . Its phase relationship is correlated, in a definite way, with the phase relationship of the folding apparatus  01 , and in particular with that of the transverse cutting arrangement  03 . 
   The phase information signal I, in the form of angle information I, or as a singular pulse at the passage of an initiator, is processed in a control device  43  and triggers the registration-correct severing process by the controlled web severing device  08 . In the case of an already phase-correlated singular pulse, the control device  43  can be embodied as a simple actuating member  43 , for example as a valve for charging the actuator  34  with a pressure medium. If the phase information I merely represents information regarding the momentary angular positions, the control device  43  has provisions for fixing, such as, for example, input provisions, of a definite nominal position and for an evaluation of the received phase information I in this regard. 
     FIGS. 2   a  to  2   c  schematically show the process of registration-correct severing, starting at the time which is already represented in  FIG. 1 , shortly after the spontaneous emergency stop-based severing of the web  02  by the emergency severing device  09 . The structural details of the device will not be again explained in what follows and the structures are also not again provided with their various reference numerals in the schematic sequence shown in  FIG. 2   a )- 2   c ). 
   Following the spontaneous severing of the continuous web  02 , by operation of the emergency severing device  09 , the continuous web  02  having the remainder R and the cutting lines S, which are identified by S 1  to S 4 , is initially moved out of the operational continuous web path. After the stoppage of the web  02 , the continuous web  02  is removed from the folding apparatus  01 , or is passed through it in a controlled manner, if need be. 
   To accomplish an initial starting or a restarting operations, after the spontaneous severing of the web  02 , the continuous web  02  is fed to the folding apparatus  01  with the correct registration. Initially, the continuous web  02  is conveyed downstream until the next cutting line S, depicted here as cutting line S 4 , or one of the succeeding cutting lines S, such as S 5 , is arranged in the cutting gap  41  of the controlled web severing device  08 , as shown in  FIG. 2   b . The controlled web severing device  08 , or its control device  43 , receives the information regarding this arrival of the cut line S 4 , S 5  by receipt of a signal representing the phase information I from the transverse cutting arrangement  03 . Now, triggering of the controlled web severing device  08 , or the activation of the actuating device  34 , takes place phase-correlated with the following transverse cutting arrangement  03  at a predetermined cutting line S, here S 4 , as shown in  FIG. 2   b . As soon as the web start containing the remainder R is prevented, by the guide element  13 , from taking the original path of web travel to the folding apparatus  01 , the blade  11  of the emergency severing device  09  can again unblock the operational continuous web path by pivoting back, as seen in  FIGS. 2   a, b . An appropriate command can, for example, be issued by the control device  43  of the controlled web severing device  08  to the control member  15  of the actuating device  12  for blade  11 , as shown in dashed lines in  FIG. 1 . 
   The continuous web section  02 ″, as shown in  FIG. 2   b ), which has been isolated following the second registration-correct severing at S 4 , can be removed from the machine. The newly formed leading edge of the continuous web  02 , which coincides with a cutting line S, such as S 4  here is conducted along the operational continuous web path through the emergency severing device  09 , or past the blades  11  thereof, to the further processing stage  01 , and, in this case, into the folding apparatus  01 . Since the newly formed leading edge of the continuous web  02  coincides with an operational cuffing line, such as line S 4  the first product section  04  formed by the transverse cutting arrangement  03  already has the correct recurring length L B , and can be picked up by the holding device  23  of the transport cylinder  22 . 
   As stated above, it is possible to unite the functions of registration-correct severing and spontaneous severing, which in  FIG. 1  are depicted as being performed by the separate severing devices  08  or  09  respectively, in a single severing device. This is desirable from the point of view of simplification and cost reduction. However, none of the severing devices  08 ,  09  in  FIG. 1  is easily suited for also taking up the function of the respectively other one. The emergency severing device  09  is constructed in such a way that it laterally deflects the leading edge of the continuous web, which is formed in the course of severing and does not conduct this leading edge to the downstream arranged folding apparatus  01 . Therefore, a manual intervention is required for conducting the newly formed leading edge, which would be formed by the emergency severing device  09 , to the folding apparatus. However, if the device  08  for registration-correct severing of the web  02  has been employed, and is in the position shown in  FIG. 2   c , the actuating device  34  can only contract to now accomplish renewed severing, with the result that the blade  32  and the cutting strip  37  of the severing device  08  must now move in a direction which is opposite to the conveying direction of the continuous web  02 . During a movement of the blade  32 , and of the cutting strip  37  in the conveying direction of the continuous web  02 , the blade is pulled along by the continuous web, so that the movement of the continuous web  02  aids in the severing process. The opposite effect occurs with a movement of the blade  32  in the opposite direction. In order to be able to sever the continuous web  02  at all, during such a retrograde movement, the severing device  08  requires the application of a considerably greater driving force than is required in the case of the movement of the blade along with the continuous web, and in which the individual webs  02  of the continuous web  02  more easily tear than being cleanly cut. A multi-use severing device  08 , which is suitable for emergency severing as well as for controlled, registration-correct severing, is represented in a perspective plan view in  FIG. 4 .  FIGS. 5   a ) to  5   d ) respectively show stages of a web severing process which can be performed with this multi-use severing device  08 . 
   The basic principle of operation of the multi-use severing device  08 , which is depicted in a perspective view in  FIG. 4 , is similar to that of the previously described controlled web severing device  08 . Functionally equal or identical parts of the two are not described in detail. The cutting strip  37  is pivotably maintained on lateral walls, which are not specifically represented, by a spindle  47  and by bearing supports  48 . The cutting blade  32  is seated in bearing supports  51 , and pivotable by rotation of a spindle  49 . In turn, these bearing supports  51  are maintained in threaded spindles, which are hidden in the drawing figure, and which spindles are rotatable around their axes in bearings  52 ,  53 . The bearings  52 ,  53  are fixedly mounted on the non-represented lateral walls. Each of the threaded spindles supports a gear wheel  54  on an end projecting past the bearing  52 , which gear wheel, by the use of a toothed belt  56  which is wrapped around it, is coupled with the gear wheel  54  of the respectively other spindle and with the movable piston of a linear actuating member  57 , whose cylinder is fastened on one of the lateral walls. By the movement of the piston of the linear actuating member  57 , the spindle  49  can be moved between a position represented in the  FIG. 4 , which is called a closed position, and an open position, in which the bearing supports  51  respectively touch the bearings  52 . 
   The two spindles  47 ,  49  support meshing gear wheels or, as represented here, gear wheel sectors  58 . The length of the teeth of these gear wheel sectors  58  is greater than the freedom of movement of the bearing supports  51  on the threaded spindles, so that the teeth of the two sectors  58  mesh in the closed, as well as in the open position. 
   The two spindles  47 ,  49 , which are coupled by the gear wheel sectors  58  can be rotatorily driven by a pneumatic cylinder  59 , a piston of which engages the spindle  47  by a lever, which is not specifically represented in  FIG. 4 . 
   In  FIG. 4 , the pneumatic cylinder  59  is extended, and the blade  32  and the cutting strip  37  are located above an imagined plane extending through the shafts of the two spindles  47 ,  49  in this position, blade  32  and strip  37  are ready to sever a continuous web, running from above, through the gap  61  between the blade  32  and the cutting strip  37 . 
   The same position is shown in  FIG. 5   a ) in a simplified sectional representation, in which the pneumatic cylinder  59 , the spindles  47 ,  49 , the blade  32 , the cutting strip  37 , as well as a continuous web  02  passing downward through the gap  61  can be seen. 
   To perform an emergency severing process or to accomplish a registration-correct severing of the continuous web  02 , the piston of the pneumatic cylinder  59  is abruptly retracted. Because of this piston retraction, the spindle  47  pivots in a counterclockwise direction in the representation of  FIG. 5   a ). The spindle  49 , which is coupled by the gear wheel sectors  58  to the spindle  47  moves in a clockwise direction, and the blade  32  and the cutting strip  37  move downward through the gap, past a position in which both levels defined by the axes of the spindles  47 ,  49  touch, and cut through the continuous web  02 . Blade  32  and strip  37  have now moved as far as into the position represented in  FIG. 5   b ). As soon as the downwardly extending continuous web  02  has been clamped between the blade  32  and the cutting strip  37 , the movement of the continuous web  02  aids the pivot movement of blade  32  and strip  37 , and therefore aids the severing process. In the course of cutting the continuous web  02 , the blade  32  and the cutting strip  37  must reach a web speed which is identical to that of the continuous web to be cut, or which is greater than the web speed, in order to prevent the trailing portion of the continuous web from becoming jammed upstream of the severing device and thus leading to running problems with the continuous web. 
   If the severing process was accomplished as a registration-correct severing process, the continuous web  02  is not stopped after severing, as was described above, but instead now continues to move uniformly through the gap  61 . It is therefore not possible to return the controlled web severing device  08  from the configuration shown in accordance with  FIG. 5   b ) directly to the configuration shown in accordance with  FIG. 5   a ) by the renewed extension of the pneumatic cylinder  59 , in order to prepare the controlled web severing device  08  for a renewed severing operation, without severing the continuous web  02  again in the process. 
   After accomplishing a successful severing using the controlled web severing device  08  of  FIG. 4 , the linear actuating member  57  is therefore actuated in order to shift the spindle  49  out of the closed position and into an open position, in which open position its distance from the spindle  47  is increased by at least the thickness of the continuous web  02 . The engagement between the teeth of the gear wheel sectors  58  is maintained during such a shifting of spindle  49 .  FIG. 5   c ) shows this spindle-shifted state. 
   The pneumatic cylinder  49  is again extended from the configuration shown in  FIG. 5   c , so that the blade  32  and the cutting strip  37  again pass through the plane of the spindle axes and take up the position shown in  FIG. 5   d . Since, in this case, in the course of their respective passing through the plane of the spindle axes, the distance between the blade  32  and the cutting strip  37  becomes at least equal to the thickness of the passing continuous web  02 , the latter is not severed. The linear actuating member  57  is now extended again so that the configuration of  FIG. 5   a ) is restored. Now, by a renewed movement into the configuration of  FIG. 5   b ), the severing device  08  can again perform an emergency web severing process, or also can perform a further registration-correct severing operation. 
   In an advantageous further development of the present invention, a device for use in the dependable severing and/or feeding of the continuous web  02  can, in principle, have a device for monitoring a width b 02  of a continuous web, as seen in  FIG. 3 , and/or a position of a continuous web, independently of the arrangement of a registration-correct severing device  08 , but in addition to such a one. 
   The device for use in monitoring the width b 02  of the continuous web has one or several detectors  44 , which scan at least the two longitudinal edges of the continuous web  02 , or of the web or the webs. As represented in  FIG. 3 , in cross section, the continuous web  02  has a folded or closed edge constituting the folded spine, and an open edge. By way of example, two detectors  44  are represented in  FIG. 3 , each having a light source, such as IR, UV or visible light and a sensor. However, the detector  44  can also be embodied as a sensor which is based on measuring reflections without a light source, or as a sensor detecting changes in magnetic or electrical fields. As represented in  FIG. 3 , several, such as, for example two, detectors  44  can be provided, which detectors  44  each extend over a partial area of, or even over the entire width of the web  02  to be detected. For local resolution of the web edge, and embodiment of the respective sensor or detector  44  as a photo-diode array is advantageous, which photo-diode array can be evaluated, with respect to the position of the edge, by the use of appropriate software. The detector  44 , or the detectors, can also be embodied as a camera, such as, for example, as a CCD camera, whose images are evaluated by appropriate evaluation software, with regard to the position of the edges, or their spacing. 
   Now, the width b 02  of the continuous web, or a signal representing it, is determined in either the above mentioned detector  44 , or in a circuit or in software to be assigned to the detectors  44 , and is compared, in a logical unit  46 , such as a comparator, summing member with an inverting input, computing unit, or the like with a predetermined, however preferably changeable maximum value M, or with a signal representing the maximum value. In another case, in which no circuit or software, which evaluates the width b 02  of the continuous web, is assigned to the detectors  44 , the logical unit  45  can have appropriate provision for evaluating the signal from the detector  44  in regard to the width b 02  of the continuous web, as well as provision for comparing the signals representing the width b 02  of the continuous web and the maximum value M. In  FIG. 3   a  the maximum width M is not exceeded, for example an output signal A of 0 is present at the output of the unit. A continuous web  02  having webs which are laterally shifted, with respect to each other and in addition having an incorrect longitudinal fold of the inner layer is represented, by way of example, in  FIG. 3   b . In this case, the width b 02  of the continuous web exceeds the predetermined maximum width M, so that a number 1 appears at the output of the unit  46 . 
   In a device for accomplishing the dependable feeding of the continuous web  02 , which device is independent of the registration-correct severing device  08 , a response to a warning signal, such as an optical or acoustic signal, is provided by the output signal A. The movement of the machine, at a speed exceeding the draw-in speed, is then blocked, and/or driving of the folding apparatus  01  is blocked or limited to the draw-in speed. 
   In the case of the integration of the device for registration-correct severing and/or feeding of the continuous web  02  by the use of a registration-correct severing device  08 , the result from the unit  46  enters the control device for triggering the registration-correct severing device  08  and/or for deactivating the spontaneous severing device  09 . 
   For example, in a first control concept in accordance with the present invention, the triggering of the registration-correct severing device  08  is only possible if, initially, the phase of the continuous web  02  is correlated with the phase of the transverse cutting arrangement  03 , i.e. the phase information I fits, and additionally the maximum width M is not exceeded. To this end, the signal A is fed to the control unit  43  and is logically taken into consideration there. 
   In another control concept in accordance with the present invention, the signal A from the logical unit  46  does not act on the control unit  43 , but instead acts on the control unit  15 . The operational continuous web path is only unblocked by the spontaneous severing device  09 , such as, for example, by reverse pivoting of the blade  11 , if the maximum width M is not exceeded. The web sections, which have possibly been registration-correctly severed by the severing device  08  in spite of the maximum width M having been exceeded on the basis of the phase information I, are shunted out by the emergency severing device  09  until the operational continuous web path has been unblocked again, as a result of an appropriate signal A. 
   If needed, in a third control concept, the signal A can act on the control unit  15 , as well as on the control unit  43 , in such a way that, as long as the maximum width M of the web  02  is exceeded, no registration-correct severing takes place, in spite of an appropriate signal I, and the operational continuous web path remains blocked. In the case of an appropriate continuous web width b 02 , the continuous web path is opened and registration-correct severing, by use of the controlled web severing device  08  is permitted, in response to an appropriate signal I. 
   In an embodiment of the present invention, which is not specifically represented, of the device for dependable severing and/or feeding, the controlled web severing device  08  is configured for performing the spontaneous severing, which is triggered by the signal N, such as an emergency stop, as well as a registration-correct severing. To this end, the signal N is, for example, supplied to an input of the control unit  43  and is given a priority for triggering the controlled web severing device  08 , or the above mentioned logical triggering device, related to the signal I and/or A is bypassed and directly passed through for triggering. In a follow-up to this emergency stop triggering, the above mentioned process is performed. In an advantageous manner, it is possible to provide a shunt, which is not specifically represented, for the continuous web downstream in place of the emergency severing device  09 , which blocks or unblocks the operational continuous web path on the basis of the signal I and/or A, in the manner of the above-described emergency severing device  09 . 
   The disclosed control and/or logical units  15 ,  43  and/or  46  are embodied to be spatially separated from each other, as a structural unit with separate partial processes, or even can be integrated, as partial processes, into the machine control device  06 . 
   In a schematic view,  FIG. 6  shows, as a further example of a continuous web processing system in accordance with the present invention, a folding apparatus  01 ′, which is configured for the simultaneous processing of two continuous webs  02 ,  02 ′. The following elements are arranged, in order, along the paths of the continuous webs  02 ,  02 ′: a catch roller pair or a traction group  19  or  19 ′, which are usable used for maintaining a preset tension of the continuous webs  02 ,  02 ′ at a former located upstream of them, which former is not represented in the drawing figure; a registration-correct web severing device  08 ,  08 ′; an emergency stop web severing device  09 ,  09 ′, as well as further web traction groups  21 ,  21 ′. The continuous web  02  subsequently reaches the surface of a transport cylinder  22 , which transport cylinder  22  can be embodied as a gripper cylinder or as a spur needle cylinder, and which is located downstream of the second traction group  21 , at the level of a cutting gap  62  formed between the transport cylinder  22  and a first blade cylinder  26 . The blade cylinder  26 , in a manner the same as the corresponding blade cylinder from  FIG. 1 , forms, together with the transport cylinder  22 , a transverse cutting arrangement  03  for severing the continuous web  02  respectively between two product sections. A second cutting cylinder  26 ′, which is part of a second transverse cutting arrangement  03 ′ and which, in a corresponding manner, cuts the second continuous web  02 ′ into product sections, is offset on the circumference of the transport cylinder  22  by exactly one product length, with respect to the cutting cylinder  26 . 
   To explain the drawing-in of continuous webs  02  and  02 ′ into the device shown in  FIG. 6 , it should initially be assumed that the transport cylinder  22  is a spur needle cylinder. The case of cylinder  22  being a gripper cylinder will be considered later. 
   In the first controlled web severing device  08 , which can be constructed as is represented in  FIG. 1  or  FIG. 4 , the first continuous web  02  is initially severed, in a manner which is synchronized with the phase relationship of the spur needle cylinder  22 , in such a way that an incomplete product section remains at the severed first continuous web  02 , whose section length is preferably only slightly less than that of a complete product section, such as, for example, 90% of the length of the latter. When the leading edge of this incomplete product section encounters the spur needle cylinder  22 , it does not touch the spur needles of the spur needle cylinder  22 , when they are extended out of the spur needle cylinder  22 , shortly before their passing through the cutting gap  62  between the cylinders  22 ,  26 . Thus, the leading, incomplete product section passes through the cutting gap  62  without being punctured. After passing through the cutting gap  62 , this leading, incomplete section is only clamped against the surface of the spur needle cylinder  22  by a roller turning along with it or by tapes. 
   The operation of the second controlled web severing device  08 ′, located in the path of the second continuous web  02 ′, is synchronized with that of the first controlled web severing device  08  in such a way that a leading edge of the second continuous web  02 ′, obtained by the severing process, meets the leading edge of the first continuous web  02  on the surface of the spur needle cylinder  22 . While this takes place, and while the first continuous web  02  is clamped to the surface of the spur needle cylinder  22 , a second, complete product section of the first continuous web  02 , which follows the first incomplete product section, is punctured by the extending spur needles shortly before entering the cutting gap  62  between the cylinders  22 ,  26 . After such a puncturing, the cutting cylinder  26  separates the second, complete product section from the first incomplete product section. 
   The two first product sections of the two continuous webs  02 ,  02 ′ then pass together through the cutting gap  62 ′ between the cylinders  22 ,  26 ′. The circumferential speed of the spur needle cylinder  22  is slightly greater than the web speed of the two continuous webs  02 ,  02 ′. Accordingly, the incomplete first section of the first continuous web  02  has already passed completely through this second cutting gap  62 ′ when the second cutting cylinder  26 ′ cuts an incomplete first section of the second continuous web  02 ′ off a following second complete product section. Here, too, the complete, second section of the second web  02 ′ is punctured prior to cutting. The two incomplete product sections are not guided, after passing through the second cutting gap, and can fall down. The following, complete product sections are dependably punctured and are conveyed on the spur needle cylinder  22  in the customary manner, which is not being specifically described here, are transversely folded after being transferred to a folding jaw cylinder  31  and are finally delivered, by the folding jaw cylinder  31 , to a paddle wheel  63 . 
   The first and second controlled web severing devices  08 ,  08 ′ can also be synchronized with the spur needle cylinder  22  in such a way that one of the continuous webs  02 ,  02 ′, or also both of the webs  02 ,  02 ′, are severed exactly at the border between two product sections. However, this would have no advantages for the way the device operates. Although the leading edge of each continuous web severed at the border would come into contact with the spur needles on the spur needle cylinder  22 , the spur needles would not be able to penetrate this edge. Instead, they would push the edge radially outward, which could lead to jams at the respective inlet of the cutting gaps  62 ,  62 ′. 
   It is not required that the leading edges of the two continuous webs  02 ,  02 ′ meet each other exactly on the spur needle cylinder  22 . It suffices that both arrive within the same product section or field on the spur needle cylinder  22  in order to assure that not merely a single one of the two first sections is caught by the spur needles and is passed on to the folding jaw cylinder. 
   If the transport cylinder  22  is embodied as a gripper cylinder, its mode of operation does not differ from that of the spur needle cylinder, provided the first and second controlled web severing devices  08 ,  08 ′ respectively each form incomplete first product sections on the continuous webs  02 ,  02 ′. The incomplete product sections cannot be grasped by the grippers and therefore fall to the ground as soon as they have passed through the second cutting gap  62 ′. An advantage results, in connection with a gripper cylinder  22 , only if the severing process taking place in the first and second controlled web severing devices  08 ,  08 ′ takes place exactly between two product sections, namely that already both first product sections of the continuous webs can be grasped and correctly processed. When employing a gripper cylinder, it is not permissible to sever one continuous web exactly at the border between two product sections and to sever the other web at a distance from the border. This would lead to the grippers only grasping one of the first product sections of the two continuous webs, which then later could not be correctly folded and could cause malfunctions. 
   In a further developed embodiment of the present device, in accordance with  FIGS. 1 to 3 , which further embodiment is not represented, with the two severing devices  08  and  09 , the web controlled severing device  08  is embodied with the degree of freedom of movement in accordance with the preferred embodiment shown in  FIGS. 4 and 5 , in addition to the first degree of freedom of movement, for example rotation, so that the controlled web severing device  08  can be brought into a closed and an open position. What was said in regard to the embodiment in accordance with  FIGS. 4 and 5  should here be additionally applied to the preferred embodiment in accordance with  FIGS. 1 to 3 . 
   While preferred embodiments of a method and devices for severing sheets from and/or feeding a web into a subsequent processing stage, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the specific printing presses used, the source of the pressurized fluid, and the like could be made without departing from the true spirit and scope of the present invention, which is accordingly to be limited only by the appended claims.