Device for separating paper sections from a paper web wound onto a paper roll, as well as a knife for separating the paper sections

Abstract

The invention relates to a device for separating paper sections (74) from a paper web wound onto a paper roll and for allowing easy manual access to the paper web that follows after the separated paper section, whereby the device comprises a cutting cylinder (40), which extends over at least the paper width, and a knife (42) that extends essentially over the entire roller width, whereby the knife (42) comprises a blade (114) and a series of teeth (120, 122, 124, 126), which are arranged spaced apart along the length of the blade, whereby the groups of teeth (120, 122, 124, 126) are separated from each other by cut-outs (128, 130, 132), and whereby the cutting roller (40) is associated with a pressure roller (44), which has a slit-shaped opening (46) and is coupled to the cutting roller (40). In order to be able to cut and dispense paper webs of high strength and elasticity reliably and trouble-free, it is intended that each of the cut-outs (128, 130, 132) comprises two cutting edges (162, 164, 166, 168), which extend parallel to each other and transversely to the longitudinal extent of the knife (42), that at least one of the cutting edges (162, 164, 166, 168) is a cutting edge of a group of teeth adjoining the cut-out, and that the cutting roller (40) comprises along its circumferential surface (134) circumferential grooves (128, 130, 132), each of which corresponds to one of the cut-outs.

What is claimed: 
     
         1 . A device ( 26 ) for separating paper sections ( 74 ) from a paper web ( 24 ) wound onto a paper roll ( 22 ) that provides easy access to the following paper web after the separated paper section has been released, whereby the device ( 26 ) comprises at least one cutting roller ( 40 ) with a width that corresponds to at least the paper width, with a fixed knife ( 42 ) that protrudes from a roller shell and substantially extends across the entire roller width, whereby the knife ( 42 ) comprises one knife blade ( 114 ) and a series of teeth ( 120 ,  122 ,  124 ,  126 ), which are spaced apart along the length of the knife blade ( 114 ), whereby the teeth ( 120 ,  126 ) or groups of teeth ( 122 ,  124 ) are separated from each other by cut-outs ( 128 ,  130 ,  132 ), and whereby the cutting roller ( 40 ) is associated with a pressure roller ( 44 ), which has a slit-shaped opening ( 46 ) and is coupled with the cutting roller ( 40 ),
 characterized in that   each of the cut-outs ( 128 ,  130 ,  132 ) has two cutting edges ( 162 ,  164 ,  166 ,  168 ), which extend in parallel to each other and transversely to the longitudinal extent of the knife ( 42 ), in that at least one of the cutting edges ( 162 ,  164 ,  166 ,  168 ) is a cutting edge of a group of teeth ( 122 ,  124 ) that borders the cut-out ( 128 ,  130 ,  132 ), and in that the cutting roller ( 40 ) comprises along its circumferential surface ( 134 ) circumferential grooves ( 136 ,  138 ,  140 ), each of which corresponds to one of the cut-outs ( 128 ,  130 ,  132 ).   
     
     
         2 . The device of  claim 1 ,
 characterized in that   the slit-shaped opening ( 46 ) of the pressure roller ( 44 ) comprises bridges ( 106 ,  108 ,  110 ) that extend along the circumferential direction, whereby a width and a separation of the bridges ( 106 ,  108 ,  110 ) correspond to a width and a separation of the cut-outs ( 128 ,  130 ,  132 ) in the knife, so that during a relative movement between the cutting roller ( 40 ) and the pressure roller ( 44 ), the bridges ( 106 ,  108 ,  110 ) engage into the cut-outs ( 128 ,  130 ,  132 ) of the knife and interact with the adjoining cutting edges ( 162 ,  164 ,  166 ,  168 ) in a scissor-like manner.   
     
     
         3 . The device of  claim 1 ,
 characterized in that   the knife ( 42 ) comprises a knife edge ( 112 ) that protrudes from the cutting roller ( 40 ) and forms an angled section.   
     
     
         4 . The device of  claim 3 ,
 characterized in that   the angled section ( 112 ) comprises the teeth ( 120 ,  126 ) or groups of teeth ( 122 ,  124 ) and is angled relative to the knife blade ( 144 ) along a deflection line at an angle α with 15°≤α≤50°, preferably α=35°.   
     
     
         5 . The device of  claim 1 ,
 characterized in that   the cutting roller ( 40 ) comprises two sections ( 116 ,  118 ), which preferably are embodied semi-circularly, and in that the blade ( 114 ) of the knife is fixed in position, such as clamped between the semi-circular sections ( 116 ,  118 ).   
     
     
         6 . The device of  claim 2 ,
 characterized in that   the separation of the bridges ( 106 ,  108 ,  110 ) of the pressure roller ( 44 ) corresponds to a width of the group of teeth ( 122 ,  124 ) of the knife edge.   
     
     
         7 . The device of  claim 1 ,
 characterized in that   the groove ( 136 ,  138 ,  140 ) is embodied with a width and a depth that correspond to the width and the depth of the cut-out ( 128 ,  130 ,  132 ).   
     
     
         8 . A knife ( 42 ) for a device ( 26 ) for separating paper sections ( 74 ) from a paper web ( 24 ) wound onto a paper roll ( 28 ), whereby the knife ( 42 ) comprises a knife blade ( 114 ) with teeth ( 120 ,  126 ) and/or groups of teeth ( 122 ,  124 ), which are arranged spaced apart relative to each other along the length of the knife blade ( 114 ), whereby the teeth ( 120 ,  126 ) and/or groups of teeth ( 122 ,  124 ) are separated from each other by cut-outs ( 128 ,  130 ,  132 ),
 characterized in that   the cut-outs ( 128 ,  130 ,  132 ) comprise two cutting edges ( 162 ,  164 ,  166 ,  168 ) that extend parallel to each other and transversely relative to the longitudinal extent of the knife ( 42 ), in that at least one of the cutting edges is a cutting edge ( 162 ,  164 ,  166 ,  168 ) of a group of teeth ( 122 ,  124 ) adjoining the cut-out, and in that the cutting edges ( 162 ,  164 ,  166 ,  168 ) of the groups of teeth ( 122 ,  124 ) possess edges ( 154 ,  156 ;  158 ,  160 ) that rise along the direction towards the cut-out ( 128 ,  130 ,  132 ).   
     
     
         9 . The knife of  claim 8 ,
 characterized in that   the groups of teeth ( 120 ,  122 ,  124 ,  126 ) are angled with respect to the blade ( 144 ) along a deflection line by an angle α with 15°≤α≤55°, preferably α=35°.   
     
     
         10 . The knife of  claim 8 ,
 characterized in that   the groups of teeth ( 120 ,  122 ,  124 ,  126 ) comprise outer teeth ( 120 ,  126 ), bordering the lateral edge of the blade, as well as at least two inner groups ( 122 ,  124 ) of teeth, whereby the geometry of a cutting edge of the inner groups of teeth is embodied in a W-shape.   
     
     
         11 . The knife of  claim 8 ,
 characterized in that   the cutting edges ( 162 ,  164 ,  166 ,  168 ) of the inner groups ( 122 ,  124 ) of teeth that border the cut-outs ( 130 ) extend parallel relative to each other.   
     
     
         12 . The knife of  claim 8 ,
 characterized in that   the width and the depth of the groove ( 136 ,  138 ,  140 ) corresponds to the width and   the depth of the cut-out ( 128 ,  130 ,  132 ).   
     
     
         13 . The knife of  claim 8 ,
 characterized in that   the knife ( 42 ) is accommodated in a cutting roller ( 40 ), and in that the cutting roller ( 40 ) along its circumferential surface ( 134 ) possesses circumferential grooves ( 136 ,  138 ,  140 ), each of which corresponds to one of the cut-outs ( 128 ,  130 ,  132 ).