Rewinding Machine, Method for Producing Logs of Web Material

Abstract

A rewinding machine including a winding system and a feed path for a web material towards the winding system is described. Positioned along the feed path is at least one air jet severing member to cause severing of the web material after winding of each log has terminated.

1 - 50 . (canceled) 
   
   
       51 . A rewinding machine for producing logs of web material comprising a winding system; a feed path of web material towards said winding system; said winding system including at least a first winding roller and a second winding roller, defining therebetween a nip through which the web material is fed; and a severing member which produces at least one jet of air to sever the web material after winding of each log has terminated, wherein said severing member is positioned along the feed path upstream of said nip. 
   
   
       52 . The rewinding machine as claimed in  claim 51 , wherein said severing member is in a substantially fixed position. 
   
   
       53 . The rewinding machine as claimed in  claim 51 , wherein said severing member moves at a substantially different speed with respect to feed speed of the web material. 
   
   
       54 . The rewinding machine as claimed in  claim 51 , further comprising a winding core feeder to feed winding cores in a core feed path towards said winding cradle. 
   
   
       55 . The rewinding machine as claimed in  claim 52 , further comprising a winding core feeder to feed winding cores in a core feed path towards said winding cradle. 
   
   
       56 . The rewinding machine as claimed in  claim 53 , further comprising a winding core feeder to feed winding cores in a core feed path towards said winding cradle. 
   
   
       57 . The rewinding machine as claimed in  claim 54 , wherein at least one feed member for said winding cores, which advances at a speed substantially equal to speed of the web material, is positioned along said core feed path. 
   
   
       58 . The rewinding machine as claimed in  claim 57 , wherein a rolling surface for said winding cores is positioned along said core feed path, forming with said feed member a feed channel for the winding cores. 
   
   
       59 . The rewinding machine as claimed in  claim 58 , wherein said severing member is positioned along said feed channel on an opposite side with respect to the rolling surface. 
   
   
       60 . The rewinding machine as claimed in  claim 59 , wherein said severing member is positioned outside the feed channel on a common side with said feed member. 
   
   
       61 . The rewinding machine as claimed in  claim 58 , wherein said rolling surface and said feed member of the cores are positioned so that the web material is between the cores and the feed member when the cores are in said core feed path. 
   
   
       62 . The rewinding machine as claimed in  claim 51 , further comprising an opposing surface positioned upstream of said nip and along which the severing member is positioned. 
   
   
       63 . The rewinding machine as claimed in  claims 62 , further comprising at least one feed member for said winding cores, which advances at a speed substantially equal to speed of the web material, is positioned along said feed path, and at least one feed member causes feed of cores along said opposing surface. 
   
   
       64 . The rewinding machine as claimed in  claim 63 , further comprising a rolling surface for said cores being positioned along said feed path and forming with said feed member a feed channel for the winding cores, and wherein said opposing surface is positioned opposite said rolling surface, the cores being inserted between said opposing surface and said rolling surface, with the web material positioned between the cores and the opposing surface. 
   
   
       65 . The rewinding machine as claimed in  claim 64 , wherein said opposing surface is a fixed surface. 
   
   
       66 . The rewinding machine as claimed in  claim 58 , wherein said feed member comprises at least one flexible member, the severing member being positioned along the feed channel defined by said rolling surface and said flexible member, on an outside of the feed channel on a common side with the flexible member. 
   
   
       67 . The rewinding machine as claimed in  claim 66 , wherein said flexible member, on which the web material fed towards said nip is in contact, is driven around a first winding roller and around at least one second guide roller. 
   
   
       68 . The rewinding machine as claimed in  claim 57 , wherein said core feed path is substantially rectilinear. 
   
   
       69 . The rewinding machine as claimed in  claim 68 , wherein said at least one feed member comprises at least one flexible member, the severing member being positioned along a feed channel defined by a rolling surface and said flexible member, on an outside of the feed channel on a common side with the flexible member; wherein said flexible member, on which the web material fed towards said nip is in contact, is driven around a first winding roller and around at least one second guide roller; and wherein said feed path, said nip and said first winding roller and said second winding roller are constructed and arranged so that the winding cores are fed along a substantially rectilinear trajectory along said core feed path and during a winding phase in contact with said first winding roller and said second winding roller. 
   
   
       70 . The rewinding machine as claimed in  claim 51 , wherein said severing member comprises at least one blowing nozzle to produce a jet of air at high speed transverse to a direction of feed of the web material. 
   
   
       71 . The rewinding machine as claimed in  claim 51 , wherein said severing member comprises at least one slotted nozzle oriented in a transverse direction with respect to a direction of feed of the web material. 
   
   
       72 . The rewinding machine as claimed in  claim 51 , wherein said severing member comprises a plurality of nozzles aligned transverse to a direction of feed of the web material. 
   
   
       73 . The rewinding machine as claimed in  claim 51 , further comprising a glue applicator to apply at least one glue to said cores. 
   
   
       74 . The rewinding machine as claimed in  claim 51 , further comprising blowing nozzles to facilitate winding of a free end of the web material around the winding core. 
   
   
       75 . The rewinding machine as claimed in  claim 74 , wherein said blowing nozzles are arranged as at least one series of said blowing nozzles positioned substantially at a level of the severing member of the web material. 
   
   
       76 . The rewinding machine as claimed in  claim 75 , wherein said at least one series of said blowing nozzles oscillates or rotates about an axis transverse with respect to a direction of feed of the web material. 
   
   
       77 . The rewinding machine as claimed in  claim 74 , wherein said at least one series of blowing nozzles is positioned on an opposite side of the core feed path with respect to a first series of said blowing nozzles and to a second series of said blowing nozzles. 
   
   
       78 . The rewinding machine as claimed in  claim 74 , devoid of means to apply glue to the winding cores, wherein winding of each log starts assisted by said blowing nozzles. 
   
   
       79 . The rewinding machine as claimed in  claim 51 , further comprising a core feed path constructed and arranged so that each core rolls along said path by an extent sufficient to transfer a portion of glue previously applied to said core to a portion of web material that will form a final free end of a log formed of the web material. 
   
   
       80 . The rewinding machine as claimed in  claim 51 , further comprising at least one electrostatic device to apply electrostatic charges to the web material and/or to winding cores to start winding of each log of the web material. 
   
   
       81 . The rewinding machine as claimed in  claim 51 , wherein said at least one jet of air is provided with a movement to follow the web material. 
   
   
       82 . The rewinding machine as claimed in  claim 51 , further comprising a suction member positioned downstream of the severing member. 
   
   
       83 . A method for producing logs of wound web material, comprising:
 feeding web material to a winding cradle, said cradle comprising at least a first winding roller and a second winding roller, the web material passing through a nip between said first winding roller and said second winding roller;   winding a first log of the web material;   severing the web material with a jet of air when winding of said first log has terminated, forming a final free end of said first log and an initial free end for winding a second log;   
     wherein said jet of air is produced upstream of said nip between the first winding roller and the second winding roller. 
   
   
       84 . The method as claimed in  claim 83 , wherein said feeding of the web material is parallel to an opposing surface at a level of which said jet of air is applied. 
   
   
       85 . The method as claimed in  claim 84 , wherein said opposing surface is fixed. 
   
   
       86 . The method as claimed in  claim 84 , wherein said opposing surface moves at a different speed with respect to a feed speed of the web material. 
   
   
       87 . The method as claimed in  claim 84 , wherein said winding of the web material to form logs is on winding cores, said winding cores being fed along an insertion path towards said winding cradle. 
   
   
       88 . The method as claimed in  claim 87 , wherein said opposing surface extends along a feed path of the web material. 
   
   
       89 . The method as claimed in  claim 87 , wherein a winding core is fed along said opposing surface, with the web material fed between the opposing surface and the winding core, the core being fed in contact with the web material at a common feed speed as with the web material. 
   
   
       90 . The method as claimed in  claim 89 , further comprising applying said jet of air downstream of a position of said core along the feed path causing severing of the web material downstream of said core. 
   
   
       91 . The method as claimed in  claim 87 , further comprising providing a feed member of the cores along said feed path. 
   
   
       92 . The method as claimed in  claim 91 , wherein said feed member of the cores is fed at a speed substantially equal to a feed speed of the web material. 
   
   
       93 . The method as claimed in  claim 91 , wherein the web material is made to pass between said feed member and a core which presses the web material against the feed member. 
   
   
       94 . The method as claimed in  claim 87 , further comprising applying glue to said winding cores. 
   
   
       95 . The method as claimed in  claim 94 , wherein said glue is applied according to at least one longitudinal line. 
   
   
       96 . The method as claimed in  claim 94 , wherein at least a portion of said glue is transferred to a portion of the web material belonging to the final free end to close the final free end of said log. 
   
   
       97 . The method as claimed in  claim 87 , wherein winding of an initial free end around said winding core is started or facilitated by one or more of said jet of air. 
   
   
       98 . The method as claimed in  claim 83 , further comprising adhering the web material to a winding core by electrostatic charges. 
   
   
       99 . The method as claimed in  claim 83 , further comprising retaining the final free end of the web material by suction. 
   
   
       100 . A rewinding machine comprising a peripheral winding unit with a severing member which produces at least one jet of air to sever web material after winding has terminated, wherein said severing member produces a jet moving in a direction of feed of the web material during a phase to sever the web material. 
   
   
       101 . A method for severing a web material provided with transverse perforation lines and moving along a feed path, comprising directing a jet of pressurized air against said web material, wherein said jet of air is moved in a direction of feed of the web material. 
   
   
       102 . A method for producing logs of web material comprising, after winding of a first log has terminated, severing the web material by a jet of pressurized air directed against the web material at a level of a transverse perforation line in the web material, and wherein subsequent to said severing of the web material, starting winding of a subsequent log, wherein said jet of pressurized air moves in a direction of feed of the perforation line to increase time of action of the jet of air on the web material in proximity to the perforation line.