Closure device for closed receptacles of plastic film

1. A plastic closure device for use with a pouch receptacle comprising:

an annulus with a cylindrical pour-out spout connectable to the receptacle;

a screw cap screwed onto the annulus;

a cylindrical piercing means open in the axial direction at both sides and displaceably mounted at said annulus, wherein catch means are present in the screw cap, said catch means moving the piercing means helically downwards when screwing off the screw cap for the first time, and wherein the piercing means is equipped with at least one cutting element, characterized in that three cutting elements are arranged distributed over a periphery of a lower edge, wherein the cutting elements are teeth and the distance of the tips of a first tooth to a second tooth on the periphery has a magnitude X, and a distance of the tip of the second tooth to the third tooth has the magnitude Y, whilst a distance of the tips of the third tooth to the first tooth is Z, and that a stiffening shoulder running in the peripheral direction is allocated to each tooth, wherein the stiffening shoulder is arranged on two teeth following the tooth in a rotational cutting direction on a lower edge of a peripheral wall of the cylindrical piercing means, and on a third tooth running ahead of this tooth in the cutting direction on a lower edge of a peripheral wall of the cylindrical piercing means, wherein the tips of all three teeth are arranged at the same height distanced to the lower edge and a cutting edge on a first and second teeth runs from a tip to the lower edge and a cutting edge on a third tooth runs from a tip to an associated stiffening shoulder, and that the receptacle to be opened is manufactured of a single-layer or multi-layer plastic film wherein the height of the stiffening shoulder corresponds to at least a third of a height of the tooth from the lower edge of the cylindrical piercing means up to the tip of the tooth, and maximally two thirds of this height.

2. A closure device according to claim 1 , wherein distances X and Y are equal.

3. A closure device according to claim 1 , wherein a gap equal to one tooth length is present between two adjacent teeth.

4. A closure device according to claim 3 , wherein the width of all three gaps is equally large.

5. A closure device according to claim 1 , wherein each tooth has a cutting edge and a trailing edge, wherein the two edges enclose an angle α of less than 150°.

6. A closure device according to claim 5 , wherein the angle α is maximally 90°, wherein the angle α at one tooth is smaller that with the two remaining ones.

7. A closure device according to claim 1 , at least one catch flank is present in the cylindrical piercing means, said flank cooperating with a catch means on the screw cap, wherein the catch flank has a ramp-like shape and with its height alignment runs directed radially to the piercing means axis, whilst the ramp edge runs parallel to a piercing means axis.

8. A closure device according to claim 7 , wherein a ramp edge is situated such that it runs through the tip of a tooth.

9. A closure device according to claim 1 , wherein the cylindrical piercing means is manufactured as one piece with the cylindrical pour-out spout, and both parts are arranged axially aligned above one another, wherein the teeth of the piercing means are arranged in a region of the upper edge of the pour-out spout and here breaking point bridges form a frangible connection between the pour-out spout and the piercing means.

10. A closure device according to claim 9 , wherein the tips of the teeth lie axially as well as radially within the region of the cylindrical pour-out spout.

11. A closure device according to claim 9 , wherein the annulus comprises a flange which on its surface is directed towards the receptacle is provided with energy conducting means.

12. A closure device according to claim 11 , wherein the energy conducting means are ribs which project perpendicularly from the flange and which with respect to the center are arranged running in a radially aligned manner.

13. A closure device according to claim 11 , wherein the energy conducting means are ribs projecting perpendicularly from the flange, wherein at least one rib at least approximately is aligned with the inner edge of the pour-out opening of the annulus.

14. A plastic closure device for use with a pouch receptacle comprising:

an annulus with a cylindrical pour-out spout connectable to the receptacle;

a screw cap screwed onto the annulus;

a cylindrical piercing means open in the axial direction at both sides and displaceably mounted at the annulus, wherein a catch means is present in the screw cap, the catch means moving the piercing means helically downwards when screwing off the screw cap for the first time;

wherein the piercing means is equipped with three cutting elements distributed over a periphery of a lower edge, wherein the cutting elements are teeth and the distance of the tips of a first tooth to a second tooth on the periphery has a magnitude X, and a distance of the tip of the second tooth to the third tooth has the magnitude Y, whilst a distance of the tips of the third tooth to the first tooth is Z, and a stiffening shoulder running in the peripheral direction is allocated to each tooth;

wherein the stiffening shoulder is arranged on two teeth following the tooth in a rotational cutting direction on a lower edge of a peripheral wall of the cylindrical piercing means, and on a third tooth running ahead of said tooth in the cutting direction on a lower edge of a peripheral wall of the cylindrical piercing means;

wherein the tips of all three teeth are arranged at the same height distanced to the lower edge and a cutting edge on first and second teeth runs from a tip to the lower edge and a cutting edge on a third tooth runs from a tip to an associated stiffening shoulder, each tooth and its associated stiffening shoulder forming said cutting elements which are standing on the lower edge of the cylindrical piercing means while each tooth is standing on the stiffening shoulder wherein the distances X and Z are equal; and

wherein a gap equal to one tooth length is present between two adjacent teeth; and

wherein the width of all three gaps is equal; and

wherein each tooth has a cutting edge and a trailing edge and wherein at least one catch flank is present in the cylindrical piercing means, the flank cooperating with a catch means on the screw cap, wherein the catch flank has a ramp and with its height alignment runs directed radially to the piercing means axis, whilst the ramp edge runs parallel to a piercing means axis; and

wherein a ramp edge is situated such that it runs through the tip of a tooth.