Abstract:
An automatic roll changer including a reel stand having a holder. At least one roll of material is rotatably mounted in that holder. A transport device is provided for transporting either at least one new material roll or at least one spent reel casing from which the material originally on the reel casing has been at least partially unwound. The transport device is adapted to more transversely to the longitudinal axes of the mounted material reel and underneath the reel stand.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This patent application is the U.S. National Phase, under 35 U.S.C. 371, of PCT/DE2003/000617, filed Feb. 26, 2003; published as WO 2003/080488 A2 and A3 on Oct. 2, 2003, and claiming priority to DE 102 13 462.6, filed Mar. 26, 2002, the disclosures of which are expressly incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention is directed to a roll changer with a roll stand, and to a method for disposing of spent cores. A transport device is used to transport new rolls and spent cores. 
   BACKGROUND OF THE INVENTION 
   Roll changers are typically employed in connection with web-fed rotary printing, for example, and are used for feeding a web of material, for example a paper web, to a printing press. In web-fed rotary printing, the web of material to be imprinted is unwound from a roll of material. This roll of material is rotatably seated in the roll changer, and it is necessary to maintain a sufficient paper tension in the web when pulling the web of material off the roll of material. When a roll of material becomes almost exhausted, i.e. the web of material wound on the roll of material is substantially unwound, this exhausting or depleted roll of material must be replaced by another fresh roll of material. Therefore, at least two separate holders, for seating two separate rolls of material are provided in roll changers. A roll change from the old or exhausting roll to the new or fresh roll of material can be performed by a manual roll change while the press is stopped. Alternatively, this roll change can be accomplished by a flying roll change, or by a stopped roll change with a web storage device. As soon as the old web of material has been replaced by the fresh web of material, the spent core of the old roll of material is removed from the holder of the roll changer to make room for a fresh roll of material for the next roll change. In other words, following each roll change it is necessary to remove an unwound spent core from the roll changer. 
   The removal of the spent cores can be performed manually by the operator at the roll changer. If the removal of the used-up cores is intended to be performed automatically, a suitable logistic arrangement for the spent cores in required. It is known in the prior art to transport spent core containers to the roll changer following a roll change. The supply tracks, on which the fresh rolls of material are being transported to the roll changers, are also used for transporting the spent core containers. As a result, it is necessary to provide for the supply of the roll changers with fresh rolls of material and for the removal of wound-off spent cores from the roll changers on a common supply track. This can lead to interferences with the production process, in particular with more complex press lines. 
   DE 196 11 494 A1 discloses an unwinding system for wound rolls. The spent cores are moved out of the roll changer in their longitudinal direction. 
   WO 95/20537 A1 shows a roll changer, with an additional lifting arrangement for spent rolls inside the roll changer. 
   DE 78 17 607 U1 describes an arrangement for suspending and removing bales of material by the use of a carrier driven by a revolving chain. 
   EP 0 454 634 A2 shows a revolving transport chain for bringing fresh cores to a winding machine. 
   DE 42 15 739 C2 describes a crane-like arrangement for transporting cores from a storage trough to a container. 
   A transport cart with a lifting device for a spent roll receiver is known from GB 2 191 967 A. 
   U.S. Pat. No. 5,934,604 discloses a roll changer with a roll stand, in whose holder at least one roll of material is rotatably seated, and with a first transport device for transporting at least one fresh roll of material. A second transport device is arranged for removing an at least partially unwound spent core. The second transport device is passed through underneath the roll stand transversely with respect to the longitudinal axis of the installed roll of material. 
   JP 10-120258 A shows a roll changer where the removal of the spent core takes place in approximately the lowest position of the holders of the roll changer. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is directed to providing roll changers with a roll stand, and to a method for disposing of spent cores. 
   In accordance with the present invention, this object is attained by the provision of a roll changer that has a roll stand with a holder which supports at least one roll of material. A transport device is used to transport fresh rolls and spent cores. The transport device passes through underneath the roll stand in a direction transverse to the longitudinal axis of the installed roll of material. Guide elements are arranged between the holder and the transport device. The transport device is continuously operated regardless of its load of spent cores. The holder is arranged at its lowest position during roll delivery. The spent cores can be placed in an elevatable receiving trough and then placed on a conveyor. The spent cores are released from the holder and delivered to a conveyor. 
   One advantage of a roll changer with a transport arrangement, in accordance with the present inventions lies in that a fixedly installed transport arrangement is provided on the roll changer, by the use of which the at least partially wound-off spent cores can be removed from the roll changer following the opening of the holders. In other words, this means that a separate transport track is being provided for the disposal of the spent cores, on which separate transport track only the spent cores are removed from the roll changer. As a result, the transport track which is used for supplying full rolls to the roll changer is relieved of spent core logistic duties and the logistics of the production processes, as a whole, are simplified. Because core containers no longer need to be transported to the individual roll changers for carrying away the spent cores, the opportunity for storing additional rolls of material in the supply system is created, instead of using that space for storage of the core containers. As a whole, reduced cycling times of the supply of the individual roll changers with rolls result, since fresh materials and spent cores are supplied or removed on separate tracks. 
   In accordance with a preferred embodiment of the present invention, the transport device is arranged in such a way that it is passed transversely underneath the roll changer with respect to the longitudinal axis of the installed web of material. Because of this, following the opening of the holders in the roll changer, the spent cores reach the transport device under the force of their inherent weight. In this way, separate drive mechanisms for use in transporting the spent cores from the holder to the transport device can be omitted. 
   Depending on the intended use, it can be advantageous to provide guide devices, for example in the form of elastic straps and/or inclined planes, between the holder for the spent cores in the roll changer and the transport device arranged underneath that holder. By the use of these guide arrangements, the course of the movement of the spent cores from the holder in the roll changer to the transport device is determined in a defined manner, so that interferences, such as, for example, stuck spent cores, can be prevented. For example, it is possible to reduce the maximum drop height of a spent core by the provision of inclined planes. Because the spent core rolls off downward on the inclined plane it, in the process, continuously travels the difference between the levels of the holder and the transport device. Furthermore, prior to opening the holder, the roll changer, with the holder supporting the spent core, should be moved in such a way that the least possible level difference exists between the spent core and the transport device. When the roll changer has reached this lowest, ejection position, for example when it is in a vertical position of the roll stand, the holder is opened and the spent core falls onto the transport device that is located underneath the holder. 
   If several roll changers are provided in a web-processing machine, the transport device can be arranged in such a way that it extends between at least two roll changers. In this way, it is possible to remove the spent cores from one or from several roll changers with one transport device. 
   In a preferred embodiment of the present invention, the transport device is continuously driven, independently of its load of spent cores. It is possible to achieve, by this, that the spent cores can be ejected from the roll changers at any time and can be removed by the transport device. Thus, a special triggering of the transport device, independently of the disposal requirements of the roll changers, can be omitted. 
   The way that the transport device is structurally configured is basically somewhat arbitrary. It is particularly advantageous if the transport device is configured, at least over portions, to revolve in an enclosed manner. For example, conveyor belts or chain conveyors can be utilized for constituting the transport device in accordance with the present invention. Depending on the required length of the transport device, it is also possible to arrange several such revolving conveyor belts or chain conveyors one behind the other. 
   In order to be able to transmit the transport movement of the transport device to the spent cores, engagement elements can be provided on the transport device. These engagement elements can, for example, protrude past the revolving conveyor belt or chain conveyor and can rest against the spent cores. By the provision of engagement elements, having an appropriate protruding length, it is also possible to convey the spent cores upward, starting at a defined initial point, without the spent cores rolling opposite their transport direction. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     A preferred embodiment of the present invention is represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
       FIG. 1 , a side elevation view, partly in cross-section of a roll changer with a transport device in accordance with the present invention, and in 
       FIG. 2 , a transverse elevation view, partly in cross-section, of the roll changer with transport device, as shown in  FIG. 1 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring initially to  FIG. 1 , there may be seen a preferred embodiment of a roll changer with a transport device in accordance with the present invention. To supply a web-processing machine, such as, for example a printing press, which is not specifically represented in  FIG. 1 , with rolls  02  of material, for example with paper rolls  02 , several roll changers  01  are provided and are arranged in line one behind the other. Only the roll changer  01  that arranged at the extreme left of the not depicted printing press is represented in  FIGS. 1 and 2 . 
   As depicted in  FIG. 1 , two rolls  02  of material, for example two paper rolls  02 , can be stored in each roll changer  01 . Here, holders  03   a  and  03   b , or  04   a  and  04   b , each of which holders is provided with an arbor  06 , as seen in  FIG. 2  at its end, support the rolls  02 . For fastening the rolls  02  on holders  03  or  04 , or for opening the holders  03  or  04  to release the rolls  02 , the holders  03  or  04  can be moved laterally toward each other or can be moved laterally away from each other. In the course of such a movement of the holders  03  or  04  together, the arbors  06  of the respective holders  03  or  04  are introduced into cores  07  which are arranged in the center of the rolls  02  and which are centered between the holders  03  or  04 , and the inserted arbors  06  are fixed in place there by the use of spreading elements, which are not specifically depicted. 
   A transport system, with driveable transport carts  08  on each of which a fresh paper roll  02  can be transported, is used to supply the roll changers  01  with fresh paper rolls  02 . In the course of a roll change performed by the roll changer  01 , a roll stand  09 , which includes the roll holders  03  and  04 , is pivoted around a pivot shaft  10  of the roll stand  09  to position the holders  03  or  04  in accordance with the desired position of the paper rolls  02 . The holders  03  and  04  are pivotable through a circular path of 360° around the central, horizontally extending pivot shaft  10  of the roll stand  09 . A straight connecting line  24  extending between the pivot shaft  10  of the roll stand  09  and an axis of rotation  05  of the holder  03 ,  04 , and a vertical line  26  extending through the pivot axis of the pivot shaft  10  enclose an opening angle α, which is less than 15°. It is also conceivable for the opening angle α to be less than 5°. 
   Following the roll change, a spent core  12 , that is the result of the unwinding of the roll  02  of material, must be removed from the roll changer  01 . For this purpose, the roll changer  01  is initially pivoted sufficiently far so that the holders  03   a  and  03   b , or  04   a  and  04   b , together with the spent core  12  fastened between them, reach a lowest, ejection point in relation to the bottom of a base  11  of the roll changer  01 . Once in this lowest, ejection position of the holders  03  or  04 , the two holders  03   a  and  03   b , or  04   a  and  04   b  are laterally moved apart. The arbors  06  are thus pulled laterally out of the spent core  12  and the spent core  12  is released. Following the opening of the holders  03   a  and  03   b , or  04   a  and  04   b , the spent core  12  falls onto a transport device  13 , which is arranged underneath the roll changers  01 , under the influence of gravity, and this released spent core  12  is removed from the roll changer  01  by the transport device  13 . The transport device  13  is preferably arranged in the beneath, and in the center of the roll stand  09 , as may be seen more clearly in  FIG. 2 . 
   The transport device  13  passes completely through the roll changer, transversely to the longitudinal axis of the roll  02  of material, and under the roll changer  01 . As seen in  FIG. 1 , the transport device  13  extends from one side of the roll changer  01  to the other side of the roll changer  01 . 
   A lifting device  30  may be anchored in the base  11  and which lifting device  30 , after having been extended in the vertical direction toward the core axis, directly receives the spent core  12  in a trough-shaped device  32  and, following lowering of the lifting device  30 , places the spent core  12  directly onto spaced conveyor belts  14 ,  16  that form the transport device  13 . The transport device  13  must be briefly stopped for this spent core placement. In this way, a defined, axially accurate placement of the spent core  12  on the conveyor belts would be possible. 
   The transport device  13  is constituted by several transport conveyor belts  14 ,  16  and an elevating conveyor belt  17 , which are arranged one behind the other in the transport direction, and which are driven by a common drive motor  18 . The conveyor belts  14 ,  16  and  17  continuously revolve during the operation of the roll changer  01 , so that spent cores  12  can be removed, at any time, and can be conveyed in the direction toward a core container  19 . Each one of the conveyor belts  14 ,  16  and  17  is formed from four side-by-side revolving belt strands, with representative belt strands  16   a ,  16   b ,  16   c ,  16   d  for conveyor belt  16 , being shown in  FIG. 2 . 
   Spaced apart, generally triangular-shaped, upwardly directed pickup elements  21  are provided on each of the conveyor belts  14  and  16  extending underneath the roll changers  01 . They come to rest against the circumference of the spent cores  12  and are helpful for transmitting the transporting movement of the conveyor belts  14 ,  16  to the spent cores  12 . Pickup elements  22 , which protrude in a shovel-like manner, are arranged on the elevating conveyor belt  17  and protrude at a length or distance, corresponding to the diameter of the spent cores  12 , past the belt strands of the elevating conveyor  17 . It is achieved by this use of pickup element  22  that when the spent cores  12  are lifted from the level of the conveyor belts  14  and  16  to the level of the upper edge of the core container  19 , the spent cores  12  do not roll back opposite to the direction of a spent core conveying movement  23 , as seen in  FIG. 1 . As a whole, the conveying movement  23  of the transport device  13  extends substantially at right angles to the longitudinal axis of the spent cores  12 . 
   By employing the transport device  13 , with its component conveyor belts  14 ,  16  and  17 , it is possible to provide for the automatic removal of spent cores  12  from several roll changers  01 , which are arranged one behind the other, to the core container  19 , which no longer needs to be transported to the individual roll changers  01 . No additional space requirement arises through the use of the subject invention, since the conveyor belts  14  and  16  are sunken into the base  11  or into the hollow box base below the roll changers  01 . 
   While a preferred embodiment of an automatic roll changer comprising a roll stand and a method for disposing of residual roll casings, in accordance with the present invention has 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 type of printing press being supplied with the material web, the specific drive for the roll stand, and the like could be made without departing from the true spirit and scope of the present invention which is to be limited only by the appended claims.