Closing device with a piercing element
A closing device arranged above a pierceable point of a closed container including a lower part with a cylindrical discharge nozzle, a screw cover and a piercing element. The piercing element, which is open on both sides, is displaced downwards in an axial direction in a screw-like manner in a screw cover in the lower part of the closing device. The piercing element has two cutting elements offset at an angle which produce a continuous, interconnected cutting line, and a displacing element which shifts a partially cut-out tab of the container from a region of the discharge nozzle.
1. A closure device of plastic which is attachable via a piercable location of a closed receptacle (B) and which has a bung-like lower part ( 2 ) with a cylindrical pour-out spout ( 20 ) which is connectable to the receptacle, and of a screw cap ( 4 ) which is screwable onto the lower part ( 2 ), as well as of a cylindrical piercing element ( 3 ) which in an axial direction is open on both sides and which is displaceably mounted in the lower part, and during a screwing-off movement of the screw cap for a first time the piercing element ( 3 ) is moved helically downwards, the closure device comprising: the piercing element ( 3 ) having at least two cutting elements ( 33 ) arranged running after one another by an offset angle (α) of less than 180° and more than 100° so that after a rotation of the piercing element ( 3 ) by the offset angle (α) a continuous cutting line of 2 α arises, and a displacing element ( 34 , 35 , 38 ) acting in a non-separated region which pushes a partly cut-out lobe of the receptacle out of a region of the pour-out spout ( 20 ).
2. A closure device according to claim 1 , wherein the displacing element is combined with a leading cutting element ( 33 ) into an element ( 34 , 38 ).
3. A closure device according to claim 2 , wherein the leading cutting element ( 33 ) has a cutting edge ( 37 ) which merges into a displacing edge ( 38 ) acting as a displacing element, the cutting element ( 37 ) is long enough that with a screwing movement after one rotation (D) of the piercing element ( 3 ) by at least approximately the offset angle α the displacing edge ( 38 ) pushes a non-separated region of the receptacle (B) out of the region of the pour-out spout ( 20 ).
4. A closure device according to claim 1 , wherein in the rotational direction of the piercing element ( 3 ) there is a displacing element ( 35 ) which is separated from the cutting element and which runs ahead of the leading cutting element ( 33 ).
5. A closure device according to claim 4 , wherein the two cutting elements ( 33 ) and the displacing element ( 35 ) are integrally connected with the piercing element ( 3 ).
6. A closure device according to claim 1 , wherein the two cutting elements ( 33 ) and the displacing element ( 34 ) are offset concentrically to an outer wall of the cylindrical piercing element ( 3 ) towards a center approximately by a wall thickness of an annular wall part ( 31 ).
7. A closure device according to claim 1 , wherein the piercing element ( 3 ) with the cutting elements ( 33 ) has a first axial length which corresponds maximally to a second axial length of the cylindrical pour-out spout ( 20 ).
8. A closure element according to claim 4 , wherein the displacing element ( 35 ) is shorter than the two cutting elements ( 33 ) by an axial distance which corresponds to an axial movement path that the two cutting elements ( 33 ) travel with a rotation of the piercing element ( 3 ) by the offset angle α.