Self-opening plastic closure

Abstract

Self-opening plastic closures having a pouring spout including a flange, a cutting member that is moveable in the spout and a screw cap for actuating the cutting member. In this invention, the cutting member carries out a translatory cutting motion by the rotational movement of the screw cap. In order to open the sealed packaging, to which the plastic closure is attached, different torques are brought to bear. According to this invention, first means and second means engage with one another successively to produce different advance paths for each revolution of the screw cap.

1 . A self-opening plastic closure ( 1 ) including a pour-out spout ( 3 ) with a flange ( 31 ) for connection to a single-layer or a multi-layer packaging foil of a closed packaging, with a cylindrical cutting element ( 4 ) movably guided within the pour-out spout ( 3 ), and with a screw cap ( 2 ) with a lateral wall ( 20 ) with an inner thread ( 23 ) and with a cover surface ( 21 ), the screw cap ( 2 ) screw-connected to the pour-out spout ( 3 ) with an outer thread ( 33 ), and the screw cap ( 2 ) and the cutting element ( 4 ) converting a screw movement of the screw cap ( 2 ) into a purely translatory relative movement of the cutting element ( 4 ) to the pour-out spout ( 3 ), the converting comprising a first advance mechanism ( 50 ) and a second advance mechanism ( 60 ) engaging one after the other and effecting different axial advance paths per revolution. 
     
     
         2 . A self-opening plastic closure according to  claim 1 , wherein the first advance mechanism ( 50 ) includes a first ramp-like annular wall ( 24 ) integrally formed on an inner side of the cover surface ( 21 ) of the screw cap ( 2 ), and a mutually opposite face wall ( 41 ) running in a ramp-like manner on the cylindrical cutting element ( 4 ). 
     
     
         3 . A self-opening plastic closure according to  claim 1 , wherein the second advance mechanism ( 60 ) includes an inner thread ( 492 ) on the cylindrical cutting element ( 4 ) and of an outer thread ( 27 ) on a second angular wall ( 26 ) arranged on an inner side of the cover surface ( 21 ) in the screw cap ( 2 ). 
     
     
         4 . A self-opening plastic closure according to  claim 3 , wherein the second annular wall ( 26 ) is arranged concentrically within the first annular wall ( 24 ). 
     
     
         5 . A self-opening plastic closure according to  claim 1 , wherein a gradient of the first advance mechanism ( 50 ) is less than a gradient of the second advance mechanism ( 60 ). 
     
     
         6 . A self-opening plastic closure according to  claim 2 , wherein the cutting element ( 4 ) on an end which lies opposite the ramp-like face wall ( 41 ) has at least one perforating tooth ( 43 ) to which a cutting edge ( 45 ) connects in a peripheral direction at both sides, and a fold-over edge ( 46 ) is present outside a region of the cutting edges and of the at least one perforating tooth ( 43 ). 
     
     
         7 . A self-opening plastic closure according to  claim 6 , wherein only one perforating tooth ( 43 ) with connecting cutting edges ( 45 ) is present, and the cutting edges ( 45 ) extend in a gapless manner about at least two thirds of a periphery and the fold-over edge ( 46 ) is arranged diametrically opposite the perforating tooth ( 43 ). 
     
     
         8 . A self-opening plastic closure according to  claim 6 , wherein at least two perforating teeth ( 43 ) present and the cutting edges extend in a gapless manner on at least two thirds of the periphery, and the fold-over edge ( 46 ) is arranged in a remaining cutting-edge free region. 
     
     
         9 . A self-opening plastic closure according to  claim 6 , wherein the cutting edges ( 46 ), which are adjacent the same perforating tooth ( 43 ) enclose an obtuse angle. 
     
     
         10 . A self-opening plastic closure according to  claim 6 , wherein an axial advance path of the first advance mechanism ( 50 ) is capable of advancing the cutting element ( 4 ) so far until a transition of the at least one cutting tooth ( 43 ) to the adjacent cutting edges ( 46 ) at least approximately lies in a plane of the flange ( 31 ) of the pour-out spout ( 3 ). 
     
     
         11 . A self-opening plastic closure according to  claim 10 , wherein the advance path of the second advance mechanism ( 60 ) is capable of advancing the cutting element ( 4 ) so far until the fold-over edge ( 46 ) at least approximately lies in the plane of the flange ( 31 ) of the pour-out spout ( 3 ). 
     
     
         12 . A self-opening plastic closure according to  claim 1 , wherein the purely translatoiy movement of the cutting element ( 4 ) relative to the pour-out spout ( 3 ) is realized by at least one axially running guide rib ( 34 ) on the inner side of a cylindrical pour-out ( 30 ) of the pour-out spout ( 3 ), and a guide recess ( 49 ) is realized in a peripheral collar ( 47 ) which is arranged at the outside on the cutting element ( 4 ). 
     
     
         13 . A self-opening plastic closure according to  claim 12 , wherein detent lobes ( 35 ) are present on the inner surface of the pour-out ( 30 ) at a height close to the flange ( 31 ), into which lobes in a lowermost advance position of the cutting element ( 4 ) its peripheral collar snaps in wherein the position is equal to the end of the advance path of the second advance mechanism ( 60 ). 
     
     
         14 . A self-opening plastic closure according to  claim 1 , wherein the pour-out spout ( 3 ) and the cutting element ( 4 ) are manufactured in a separable manner as a single piece, as one component ( 70 ). 
     
     
         15 . A self-opening plastic closure according to  claim 2 , wherein the second annular wall ( 26 ) is arranged concentrically within the first annular wall ( 24 ).