Core member for an absorbent sheet roll

Abstract

A hollow cylindrical core member ( 17 ) suitable for supporting a roll ( 11 ) of absorbent sheet material. The core member ( 17 ) includes a central axis ( 22 ), an outer cylindrical surface ( 20 ), and an inner cylindrical surface ( 23 ). The inner cylindrical surface ( 23 ) includes engagement means suitable for rotationally locking said core member ( 17 ). The engagement means include at least one elongated recess ( 19 ) and/or projection ( 29 ) extending helically along said inner cylindrical surface ( 23 ), or at least one elongated projection ( 29 ) extending in a direction of said central axis ( 22 ).

1 . A hollow cylindrical core member suitable for supporting a roll of absorbent sheet material, said core member comprising a central axis, an outer cylindrical surface, and an inner cylindrical surface, said inner cylindrical surface comprising engagement means configured for rotationally locking said core member with a shaft of a dispenser that is configured for dispensing absorbent sheet material, said engagement means comprising:
 at least one elongated recess and/or projection extending helically along said inner cylindrical surface, or   at least one elongated projection extending in a direction of said central axis.   
     
     
         2 . The core member according to  claim 1 , wherein said at least one elongated recess and/or projection extends continuously over at least 20% of the total axial length of said core member. 
     
     
         3 . The core member according to  claim 1 , wherein a radial depth of said at least one elongated recess is smaller than a wall thickness of said core member at a location without a recess. 
     
     
         4 . The core member according to  claim 1 , wherein said at least one elongated recess extends completely through a cylindrical wall of said core member, such that a through hole is formed in said core member. 
     
     
         5 . The core member according to  claim 1 , wherein said core member is formed from a helically wound first band having a width and forming a helical winding angle with respect to said central axis, wherein said helical winding angle and said width is selected such that a gap is formed between edges of consecutive windings of said first band, which gap at least partly forms said recess. 
     
     
         6 . The core member according to  claim 5 , wherein said core member comprises at least one additional material layer being arranged on a circumferential outer surface of said helically wound first band, wherein said at least one additional material layer covers said gap. 
     
     
         7 . The core member according to  claim 5 , wherein a width of said gap is smaller than half the width of said first band in a direction perpendicular to the helical winding direction of said first band. 
     
     
         8 . The core member according to  claim 1 , wherein said core member is formed of at least two layers of helically wound band, and both said layers of wound band being wound in the same winding direction. 
     
     
         9 . The core member according to  claim 1 , wherein said elongated recess is formed by mechanically processing the inner surface of said core member. 
     
     
         10 . The core member according to  claim 1 , wherein said core member is made of moulded pulp or plastic material. 
     
     
         11 . The core member according to  claim 1 , wherein said core member comprises a single material layer, or multiple material layers. 
     
     
         12 . The core member according to  claim 1 , wherein said core member is formed by at least one hollow cylindrical plug element that is configured to be inserted into a central hole of a coreless roll, wherein said engagement means is formed at an inner cylindrical surface of said plug element. 
     
     
         13 . The core member according to  claim 12 , wherein said core member is formed by two hollow cylindrical plug elements, each of which being suitable to be inserted into a central hole of a coreless roll. 
     
     
         14 . The core member according to  claim 1 , wherein a height of said elongated projection is substantially larger than a wall thickness of said core member at a location without an elongated projection. 
     
     
         15 . Dispenser assembly comprising a dispenser suitable for dispensing absorbent sheet material from a roll, and a core member according to  claim 1 , wherein said dispenser assembly comprises: a dispenser body, a shaft on which said core member is arranged, wherein said shaft is rotatably coupled to said dispenser body, each of said shaft and said core member comprising engagement means that are in cooperating mating position, such that said shaft is rotationally locked with said core member. 
     
     
         16 . Dispenser assembly according  claim 15 , wherein said dispenser assembly further comprising: an electrical machine and an electrical storage system for storing electrical energy, wherein said electrical machine is rotatably coupled to said shaft, wherein externally caused rotation of said core member drives said electrical machine, thereby facilitating generation of electrical energy that is stored in said electrical storage system, and wherein said electrical machine is configured to be powered by electrical energy from said electrical storage system for temporarily rotating said core member. 
     
     
         17 . The core member according to  claim 1 , wherein said at least one elongated recess and/or projection extends continuously over at least 50% of the entire axial length of said core member. 
     
     
         18 . The core member according to  claim 1 , wherein said at least one elongated recess and/or projection extends continuously over the entire axial length of said core member. 
     
     
         19 . The core member according to  claim 5 , wherein a width of said gap is smaller than 25% of the width of said first band in a direction perpendicular to the helical winding direction of said first band.